Merge remote-tracking branch 'origin/hypre-runtime-compute-policy' into apps-dev

Merge remote-tracking branch 'origin/feature/askinner/hdiv-saddle-point-solver' into apps-dev
Merge remote-tracking branch 'origin/master' into hypre-runtime-compute-policy
2023-10-27 09:22:16 -07:00 · 2023-10-27 09:22:12 -07:00 · 2023-10-27 09:03:44 -07:00 · 2023-08-29 21:16:35 -07:00 · 2023-08-25 14:36:14 -07:00
556 changed files with 20379 additions and 37867 deletions
@@ -128,13 +128,6 @@ examples/amgx/sol.gf
 examples/amgx/mesh.*
 examples/amgx/sol.*

-examples/caliper/ex1
-examples/caliper/ex1p
-examples/caliper/refined.mesh
-examples/caliper/sol.gf
-examples/caliper/mesh.*
-examples/caliper/sol.*
-
 examples/ginkgo/ex1
 examples/ginkgo/refined.mesh
 examples/ginkgo/sol.gf
@@ -273,7 +266,6 @@ miniapps/navier/*_output
 miniapps/nurbs/nurbs_ex1
 miniapps/nurbs/nurbs_ex1p
 miniapps/nurbs/nurbs_ex11p
-miniapps/nurbs/nurbs_printfunc
 miniapps/nurbs/nurbs_patch_ex1
 miniapps/nurbs/nurbs_curveint
 miniapps/nurbs/refined.mesh
@@ -283,10 +275,6 @@ miniapps/nurbs/mode_*
 miniapps/nurbs/Example1*
 miniapps/nurbs/sin-fit.mesh
 miniapps/nurbs/CurveInt
-miniapps/nurbs/nurbs_naca_cmesh
-miniapps/nurbs/naca-cmesh.mesh
-miniapps/nurbs/glvis_naca-cmesh.mesh
-miniapps/nurbs/Naca_cmesh

 miniapps/performance/ex1
 miniapps/performance/ex1p
@@ -311,7 +299,7 @@ miniapps/tools/convert-dc
 miniapps/tools/lor-transfer
 miniapps/tools/plor-transfer
 miniapps/tools/get-values
-miniapps/tools/tmop-check-metric
+miniapps/tools/check-tmop-metric
 miniapps/tools/tmop-metric-magnitude
 miniapps/tools/nodal-transfer
 miniapps/tools/ParaView
@@ -342,7 +330,6 @@ miniapps/toys/mondrian.mesh
 miniapps/solvers/block-solvers
 miniapps/solvers/lor_solvers
 miniapps/solvers/plor_solvers
-miniapps/solvers/lor_elast
 miniapps/solvers/ParaView
 miniapps/solvers/mesh.*
 miniapps/solvers/sol.*
@@ -11,44 +11,6 @@
 Version 4.6.1 (development)
 ===========================

-Discretization improvements
---------------------------
- Introduced support for higher order non conformal Nedelec elements on
-  simplices in ParMesh.
- Introduced support for internal boundary elements in nonconformal adapted
-  meshes.
-
- Added functionality for construction of cut-surface and cut-volume
-  IntegrationRules through a moment-fitting approach. The cut is specified by
-  the zero level set of a Coefficient. See fem/intrules_cut.hpp and Example 38.
-
-GPU support
----------------------------
- Added support for full assembly on simplices.
- Added functionality for BilinearFormIntegrators to use kernels that work for both
-  tensor and unstructured elements.
- Added partial assembly for linear elasticity. Does not use sum factorization for now.
-
-New and updated examples and miniapps
-------------------------------------
- Added miniapp to demonstrate new elasticity integrator and unstructured element GPU support,
-  and a block diagonal preconditioner using low order refinement. Allows comparison with
-  currently existing legacy mode integrator. See miniapps/solvers/lor_elast.
-
-Miscellaneous
-------------
- Added support for single and double precision, with corresponding hypre build.
-  Generalized the floating point type from `double` to `real_t`.
-
- The ReadCubit Genesis mesh importer has been rewritten to improve readability.
-
- Updated the Doxygen documentation style, which now requires Doxygen version
-  1.9.8 or later. See the doc/ directory.
-
- Improved thread safety for global variables in the library, for example
-  IntegrationRules IntRules, RefinedIntRules, GeometryRefiner
-  GlobGeometryRefiner, and FiniteElement::dof2quad_array.
-

 Version 4.6, released on September 27, 2023
 ===========================================
@@ -69,7 +31,6 @@ Meshing improvements
  * The edge to knot map for NURBS meshes can be determined automatically. It is
    no longer needed to specify this in the NURBS mesh.
  * Added curve interpolation method for NURBS.
-  * Added new small miniapp for printing of shape functions of a KnotVector
  * See miniapps/nurbs for example meshes and miniapps.

 Discretization improvements
@@ -116,8 +77,6 @@ Linear and nonlinear solvers

 - Added HIP support to the PETSc and SUNDIALS interfaces.

- Efficient GPU-accelerated LOR assembly now supports surface meshes.
-
 New and updated examples and miniapps
 -------------------------------------
 - Added a new H(div) solver miniapp demonstrating the use of a matrix-free
@@ -139,9 +139,10 @@ if (MFEM_USE_CUDA)
      set(CMAKE_CUDA_HOST_LINK_LAUNCHER ${CMAKE_CXX_COMPILER})
   endif()
   set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} ${CUDA_FLAGS}")
-   find_package(CUDAToolkit REQUIRED)
   set(CUSPARSE_FOUND TRUE)
-   get_target_property(CUSPARSE_LIBRARIES CUDA::cusparse LOCATION)
+   set(CUSPARSE_LIBRARIES "cusparse")
+   set(CUBLAS_FOUND TRUE)
+   set(CUBLAS_LIBRARIES "cublas")
 endif()

 if (XSDK_ENABLE_C)
@@ -530,7 +531,7 @@ find_package(Threads REQUIRED)
 set(MFEM_TPLS OPENMP HYPRE LAPACK BLAS SuperLUDist STRUMPACK METIS SuiteSparse
    SUNDIALS PETSC SLEPC MUMPS AXOM FMS CONDUIT Ginkgo GNUTLS GSLIB
    NETCDF MPFR PUMI HIOP POSIXCLOCKS MFEMBacktrace ZLIB OCCA CEED RAJA UMPIRE
-    ADIOS2 CUSPARSE MKL_CPARDISO MKL_PARDISO AMGX CALIPER CODIPACK
+    ADIOS2 CUBLAS CUSPARSE MKL_CPARDISO MKL_PARDISO AMGX CALIPER CODIPACK
    BENCHMARK PARELAG MPI_CXX HIP HIPSPARSE MOONOLITH BLITZ ALGOIM ENZYME)

 # Add all *_FOUND libraries in the variable TPL_LIBRARIES.
@@ -640,34 +641,16 @@ if (NOT ("${PROJECT_SOURCE_DIR}" STREQUAL "${PROJECT_BINARY_DIR}"))
  foreach(Header mfem.hpp mfem-performance.hpp)
    message(STATUS
      "Writing substitute header --> \"${Header}\"")
-    file(WRITE "${PROJECT_BINARY_DIR}/${Header}.tmp"
+    file(WRITE "${PROJECT_BINARY_DIR}/${Header}"
 "// Auto-generated file.
 #define MFEM_CONFIG_FILE \"${PROJECT_BINARY_DIR}/config/_config.hpp\"
 #include \"${PROJECT_SOURCE_DIR}/${Header}\"
 ")
-
-    execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different 
-      "${PROJECT_BINARY_DIR}/${Header}.tmp"
-      "${PROJECT_BINARY_DIR}/${Header}"
-    )
-    execute_process(COMMAND ${CMAKE_COMMAND} -E remove
-      "${PROJECT_BINARY_DIR}/${Header}.tmp"
-    )
-
    # This version will be installed in the top include directory:
-    file(WRITE "${PROJECT_BINARY_DIR}/InstallHeaders/${Header}.tmp"
+    file(WRITE "${PROJECT_BINARY_DIR}/InstallHeaders/${Header}"
 "// Auto-generated file.
 #include \"mfem/${Header}\"
 ")
-
-    execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different 
-      "${PROJECT_BINARY_DIR}/InstallHeaders/${Header}.tmp"
-      "${PROJECT_BINARY_DIR}/InstallHeaders/${Header}"
-    )
-    execute_process(COMMAND ${CMAKE_COMMAND} -E remove
-      "${PROJECT_BINARY_DIR}/InstallHeaders/${Header}.tmp"
-    )
-
  endforeach()
 endif()

@@ -359,8 +359,6 @@ Before you can start, you need a GitHub account, here are a few suggestions:
    conflicted files in the commit message.
  - All significant new features and changes should be documented in CHANGELOG.
  - New examples and miniapps should have documentation on the MFEM webpage.
-  - The general floating-point type `real_t` should be used, rather than
-    `float` or `double`, except in special cases where only one is possible.


 ### Pull Requests
@@ -659,7 +659,8 @@ The specific libraries and their options are:
  requires the PT-Scotch and Scalapack libraries as well as ParMETIS, which
  includes METIS 5 in its distribution. Starting with STRUMPACK v2.2.0, ParMETIS
  and PT-Scotch are optional dependencies.
-  The support for STRUMPACK was added in MFEM v3.3.2.
+  The support for STRUMPACK was added in MFEM v3.3.2 and it requires STRUMPACK
+  2.0.0 or later.
  URL: http://portal.nersc.gov/project/sparse/strumpack
  Options: STRUMPACK_OPT, STRUMPACK_LIB.
  Versions: STRUMPACK >= 3.0.0.
@@ -796,7 +797,7 @@ The specific libraries and their options are:
  URL: https://github.com/CEED/libCEED
       https://ceed.exascaleproject.org/libceed
  Options: CEED_DIR, CEED_OPT, CEED_LIB.
-  Versions: libCEED >= 0.12.
+  Versions: libCEED >= 0.10.

 - RAJA (optional), used when MFEM_USE_RAJA = YES.
  Beginning with MFEM v4.5.1, only RAJA v2022.10.3+ is supported.
@@ -63,8 +63,6 @@ set(MFEM_USE_ALGOIM @MFEM_USE_ALGOIM@)
 set(MFEM_USE_BENCHMARK @MFEM_USE_BENCHMARK@)
 set(MFEM_USE_PARELAG @MFEM_USE_PARELAG@)
 set(MFEM_USE_ENZYME @MFEM_USE_ENZYME@)
-set(MFEM_USE_DOUBLE @MFEM_USE_DOUBLE@)
-set(MFEM_USE_SINGLE @MFEM_USE_SINGLE@)

 set(MFEM_CXX_COMPILER "@CMAKE_CXX_COMPILER@")
 set(MFEM_CXX_FLAGS "@CMAKE_CXX_FLAGS@")
@@ -201,10 +201,4 @@
 // Enable Enzyme for AD
 #cmakedefine MFEM_USE_ENZYME

-// Use double-precision floating point type
-#cmakedefine MFEM_USE_DOUBLE
-
-// Use single-precision floating point type
-#cmakedefine MFEM_USE_SINGLE
-
 #endif // MFEM_CONFIG_HEADER
@@ -14,13 +14,9 @@
 #   - HYPRE_LIBRARIES
 #   - HYPRE_INCLUDE_DIRS
 #   - HYPRE_VERSION
-#   - HYPRE_USING_CUDA (internal)
 #   - HYPRE_USING_HIP (internal)

 if (HYPRE_FOUND)
-  if (HYPRE_USING_CUDA)
-    find_package(CUDAToolkit REQUIRED)
-  endif()
  if (HYPRE_USING_HIP)
    find_package(rocsparse REQUIRED)
    find_package(rocrand REQUIRED)
@@ -31,20 +27,6 @@ endif()
 include(MfemCmakeUtilities)
 mfem_find_package(HYPRE HYPRE HYPRE_DIR "include" "HYPRE.h" "lib" "HYPRE"
  "Paths to headers required by HYPRE." "Libraries required by HYPRE."
-  CHECK_BUILD HYPRE_USING_CUDA FALSE
-  "
-#undef HYPRE_USING_CUDA
-#include <HYPRE_config.h>
-
-#ifndef HYPRE_USING_CUDA
-#error HYPRE is built without CUDA.
-#endif
-
-int main()
-{
-   return 0;
-}
-"
  CHECK_BUILD HYPRE_USING_HIP FALSE
  "
 #undef HYPRE_USING_HIP
@@ -75,16 +57,6 @@ if (HYPRE_FOUND AND (NOT HYPRE_VERSION))
  endif()
 endif()

-if (HYPRE_FOUND AND HYPRE_USING_CUDA)
-  find_package(CUDAToolkit REQUIRED)
-  get_target_property(CUSPARSE_LIBRARIES CUDA::cusparse LOCATION)
-  get_target_property(CURAND_LIBRARIES CUDA::curand LOCATION)
-  list(APPEND HYPRE_LIBRARIES ${CUSPARSE_LIBRARIES} ${CURAND_LIBRARIES})
-  set(HYPRE_LIBRARIES ${HYPRE_LIBRARIES} CACHE STRING
-      "HYPRE libraries + dependencies." FORCE)
-  message(STATUS "Updated HYPRE_LIBRARIES: ${HYPRE_LIBRARIES}")
-endif()
-
 if (HYPRE_FOUND AND HYPRE_USING_HIP)
  find_package(rocsparse REQUIRED)
  find_package(rocrand REQUIRED)
@@ -201,10 +201,4 @@
 // Enable the Enzyme LLVM plugin
 // #define MFEM_USE_ENZYME

-// Use double-precision floating point type
-// #define MFEM_USE_DOUBLE
-
-// Use single-precision floating point type
-// #define MFEM_USE_SINGLE
-
 #endif // MFEM_CONFIG_HEADER
@@ -64,8 +64,6 @@ MFEM_USE_CODIPACK      = @MFEM_USE_CODIPACK@
 MFEM_USE_BENCHMARK     = @MFEM_USE_BENCHMARK@
 MFEM_USE_PARELAG       = @MFEM_USE_PARELAG@
 MFEM_USE_ENZYME        = @MFEM_USE_ENZYME@
-MFEM_USE_DOUBLE        = @MFEM_USE_DOUBLE@
-MFEM_USE_SINGLE        = @MFEM_USE_SINGLE@

 # Compiler, compile options, and link options
 MFEM_CXX       = @MFEM_CXX@
@@ -66,8 +66,6 @@ option(MFEM_USE_CODIPACK "Enable automatic differentiation (AD) using CoDiPack"
 option(MFEM_USE_BENCHMARK "Enable Google Benchmark" OFF)
 option(MFEM_USE_PARELAG "Enable ParELAG" OFF)
 option(MFEM_USE_ENZYME "Enable Enzyme" OFF)
-option(MFEM_USE_DOUBLE "Double precision" ON)
-option(MFEM_USE_SINGLE "Single precision" OFF)

 # Optional overrides for autodetected MPIEXEC and MPIEXEC_NUMPROC_FLAG
 # set(MFEM_MPIEXEC "mpirun" CACHE STRING "Command for running MPI tests")
@@ -108,7 +106,12 @@ set(HYPRE_DIR "${MFEM_DIR}/../hypre/src/hypre" CACHE PATH
 # If hypre was compiled to depend on BLAS and LAPACK:
 # set(HYPRE_REQUIRED_PACKAGES "BLAS" "LAPACK" CACHE STRING
 #     "Packages that HYPRE depends on.")
-# CUDA and HIP dependencies for HYPRE are handled in FindHYPRE.cmake.
+if (MFEM_USE_CUDA)
+   # This is only necessary when hypre is built with cuda:
+   set(HYPRE_REQUIRED_LIBRARIES "-lcusparse" "-lcurand" CACHE STRING
+       "Libraries that HYPRE depends on.")
+endif()
+# HIP dependency for HYPRE is handled in FindHYPRE.cmake.

 set(METIS_DIR "${MFEM_DIR}/../metis-4.0" CACHE PATH "Path to the METIS library.")

@@ -154,8 +157,7 @@ set(STRUMPACK_DIR "${MFEM_DIR}/../STRUMPACK-build" CACHE PATH
 # STRUMPACK may also depend on "OpenMP", depending on how it was compiled.
 # Starting with v2.2.0 of STRUMPACK, ParMETIS and Scotch are optional.
 set(STRUMPACK_REQUIRED_PACKAGES "MPI" "MPI_Fortran" "ParMETIS" "METIS"
-    "Scotch/ptscotch/ptscotcherr/scotch/scotcherr"
-    "ScaLAPACK" "LAPACK" "BLAS" CACHE STRING
+    "ScaLAPACK" "Scotch/ptscotch/ptscotcherr/scotch/scotcherr" CACHE STRING
    "Additional packages required by STRUMPACK.")
 # If the MPI package does not find all required Fortran libraries:
 # set(STRUMPACK_REQUIRED_LIBRARIES "gfortran" "mpi_mpifh" CACHE STRING
@@ -167,8 +167,6 @@ MFEM_USE_CODIPACK      = NO
 MFEM_USE_BENCHMARK     = NO
 MFEM_USE_PARELAG       = NO
 MFEM_USE_ENZYME        = NO
-MFEM_USE_DOUBLE        = YES
-MFEM_USE_SINGLE        = NO

 # MPI library compile and link flags
 # These settings are used only when building MFEM with MPI + HIP
@@ -333,30 +331,16 @@ STRUMPACK_OPT = -I$(STRUMPACK_DIR)/include $(SCOTCH_OPT)
 STRUMPACK_LIB = -L$(STRUMPACK_DIR)/lib -lstrumpack $(MPI_FORTRAN_LIB)\
 $(SCOTCH_LIB) $(SCALAPACK_LIB)

-# Ginkgo library configuration
+# Ginkgo library configuration (currently not needed)
 GINKGO_DIR = @MFEM_DIR@/../ginkgo/install
-GINKGO_SEARCH_DIR = $(subst @MFEM_DIR@,$(MFEM_DIR),$(GINKGO_DIR))
 GINKGO_BUILD_TYPE=Release
 ifeq ($(MFEM_USE_GINKGO),YES)
   BASE_FLAGS = -std=c++14
 endif
 GINKGO_OPT = -isystem $(GINKGO_DIR)/include
-GINKGO_LIB_DIR = $(sort $(dir $(wildcard\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*.a\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*.so\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*.dylib\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*.dll)))
-GINKGO_LINK_LIB_DIR = $(GINKGO_DIR)$(subst $(GINKGO_SEARCH_DIR),,$(GINKGO_LIB_DIR))
-ALL_GINKGO_LIBS_DEBUG = $(notdir $(basename $(wildcard\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*d.a\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*d.so\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*d.dylib\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*d.dll)))
-ALL_GINKGO_LIBS = $(notdir $(basename $(wildcard\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*.a\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*.so\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*.dylib\
- $(GINKGO_SEARCH_DIR)/lib*/libginkgo*.dll)))
+GINKGO_LIB_DIR = $(sort $(dir $(wildcard $(GINKGO_DIR)/lib*/libginkgo*.a  $(GINKGO_DIR)/lib*/libginkgo*.so $(GINKGO_DIR)/lib*/libginkgo*.dylib $(GINKGO_DIR)/lib*/libginkgo*.dll)))
+ALL_GINKGO_LIBS_DEBUG = $(notdir $(basename $(wildcard $(GINKGO_DIR)/lib*/libginkgo*d.a  $(GINKGO_DIR)/lib*/libginkgo*d.so $(GINKGO_DIR)/lib*/libginkgo*d.dylib $(GINKGO_DIR)/lib*/libginkgo*d.dll)))
+ALL_GINKGO_LIBS = $(notdir $(basename $(wildcard $(GINKGO_DIR)/lib*/libginkgo*.a  $(GINKGO_DIR)/lib*/libginkgo*.so $(GINKGO_DIR)/lib*/libginkgo*.dylib $(GINKGO_DIR)/lib*/libginkgo*.dll)))
 ALL_GINKGO_LIBS_RELEASE = $(filter-out $(ALL_GINKGO_LIBS_DEBUG),$(ALL_GINKGO_LIBS))
 GINKGO_LINK = $(subst libginkgo,-lginkgo,$(ALL_GINKGO_LIBS_RELEASE))
 ifeq ($(GINKGO_BUILD_TYPE),Debug)
@@ -365,8 +349,7 @@ ifeq ($(GINKGO_BUILD_TYPE),Debug)
  endif
 else
 endif
-GINKGO_LIB = $(XLINKER)-rpath,$(GINKGO_LINK_LIB_DIR) -L$(GINKGO_LINK_LIB_DIR)\
- $(GINKGO_LINK)
+GINKGO_LIB = $(XLINKER)-rpath,$(GINKGO_LIB_DIR) -L$(GINKGO_LIB_DIR) $(GINKGO_LINK)

 # AmgX library configuration
 AMGX_DIR = @MFEM_DIR@/../amgx
@@ -38,14 +38,14 @@ all: header config-mk
 MPI = $(MFEM_USE_MPI:NO=)
 GHV_CXX ?= $(MFEM_CXX)
 GHV = get_hypre_version
-GHV_FLAGS = $(MFEM_CXXFLAGS) $(subst @MFEM_DIR@,$(if $(MFEM_DIR),$(MFEM_DIR),..),$(HYPRE_OPT))
+GHV_FLAGS = $(subst @MFEM_DIR@,$(if $(MFEM_DIR),$(MFEM_DIR),..),$(HYPRE_OPT))
 SMX = $(if $(MFEM_USE_PUMI:NO=),MFEM_USE_SIMMETRIX)
 SMX_PATH = $(PUMI_DIR)/include/gmi_sim.h
 SMX_FILE = $(subst @MFEM_DIR@,$(if $(MFEM_DIR),$(MFEM_DIR),..),$(SMX_PATH))
 MUMPS = $(MFEM_USE_MUMPS:NO=)
 GMV_CXX ?= $(MFEM_CXX)
 GMV = get_mumps_version
-GMV_FLAGS = $(MFEM_CXXFLAGS) $(subst @MFEM_DIR@,$(if $(MFEM_DIR),$(MFEM_DIR),..),$(MUMPS_OPT))
+GMV_FLAGS = $(subst @MFEM_DIR@,$(if $(MFEM_DIR),$(MFEM_DIR),..),$(MUMPS_OPT))

 $(GHV): $(SRC)$(GHV).cpp
 	$(call mfem-info, Determining HYPRE version ...)
@@ -110,4 +110,3 @@ config-mk:

 clean:
 	rm -f $(CONFIG_HPP) $(CONFIG_MK) sample-runs-build.log
-	rm -f $(GHV) $(GHV).out $(GMV) $(GMV).out
@@ -315,7 +315,7 @@ function extract_sample_runs()
   sruns=`grep -v "^//.*  mpirun .* ${app}" "${src}" |
          grep "^//.*  ${app}" |
          sed -e "s/.*  ${app}/${vg_app}/g"`
-   runs="${sruns}"$'\n'"${pruns}"
+   runs="${sruns}${pruns}"
   if [ "$skip_gen_meshes" == "yes" ]; then
      runs=`printf "%s" "$runs" | grep -v ".* -m .*\.gen"`
   fi
@@ -112,7 +112,6 @@ namespace mfem {
 * - <a class="el" href="ex36p_8cpp_source.html">Example 36p</a>: parallel Proximal Galerkin FEM for the obstacle problem
 * - <a class="el" href="ex37_8cpp_source.html">Example 37</a>: Topology optimization
 * - <a class="el" href="ex37p_8cpp_source.html">Example 37p</a>: parallel topology optimization
- * - <a class="el" href="ex38_8cpp_source.html">Example 38</a>: cut-surface and cut-volume integration
 *
 * <H4>AmgX Examples</H4>
 * - Variants of Examples
@@ -216,7 +215,6 @@ namespace mfem {
 * - <a class="el" href="generate__random__field_8cpp_source.html">SPDE Solvers</a>: SPDE solver random field generation
 * - <a class="el" href="pdiffusion_8cpp_source.html">DPG Diffusion example</a>: DPG formulation for the diffusion problem
 * - <a class="el" href="pmaxwell_8cpp_source.html">DPG Maxwell example</a>: DPG formulation for the indefinite Maxwell problem
- * - <a class="el" href="lor__elast_8cpp_source.html">LOR Elasticity</a>: solve linear elasticity with LOR preconditioning on GPUs
 *
 * See also the <a class="el" href="https://mfem.org/examples/">examples documentation</a> online.
 */
@@ -14,7 +14,7 @@ If not already available, Doxygen can be downloaded from

   http://www.doxygen.org

-We recommend using version 1.9.8 or later.
+We recommend using version 1.8 or later.

 To build the documentation, simply type "make" in the doc/ directory. This will
 create the file CodeDocumentation.html, which can be viewed in any web browser.
@@ -1,3 +0,0 @@
-html {
-    --content-maxwidth: auto;
-}
@@ -1,78 +0,0 @@
-<!-- HTML header for doxygen 1.9.6-->
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml" lang="$langISO">
-<head>
-<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
-<meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen $doxygenversion"/>
-<meta name="viewport" content="width=device-width, initial-scale=1"/>
-<!--BEGIN PROJECT_NAME--><title>$projectname: $title</title><!--END PROJECT_NAME-->
-<!--BEGIN !PROJECT_NAME--><title>$title</title><!--END !PROJECT_NAME-->
-<link href="$relpath^tabs.css" rel="stylesheet" type="text/css"/>
-<!--BEGIN DISABLE_INDEX-->
-  <!--BEGIN FULL_SIDEBAR-->
-<script type="text/javascript">var page_layout=1;</script>
-  <!--END FULL_SIDEBAR-->
-<!--END DISABLE_INDEX-->
-<script type="text/javascript" src="$relpath^jquery.js"></script>
-<script type="text/javascript" src="$relpath^dynsections.js"></script>
-$treeview
-$search
-$mathjax
-$darkmode
-<link href="$relpath^$stylesheet" rel="stylesheet" type="text/css" />
-$extrastylesheet
-<script type="text/javascript" src="$relpath^doxygen-awesome-darkmode-toggle.js"></script>
-<script type="text/javascript">
-    DoxygenAwesomeDarkModeToggle.init()
-</script>
-</head>
-<body>
-<!--BEGIN DISABLE_INDEX-->
-  <!--BEGIN FULL_SIDEBAR-->
-<div id="side-nav" class="ui-resizable side-nav-resizable"><!-- do not remove this div, it is closed by doxygen! -->
-  <!--END FULL_SIDEBAR-->
-<!--END DISABLE_INDEX-->
-
-<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
-
-<!--BEGIN TITLEAREA-->
-<div id="titlearea">
-<table cellspacing="0" cellpadding="0">
- <tbody>
- <tr id="projectrow">
-  <!--BEGIN PROJECT_LOGO-->
-  <td id="projectlogo"><img alt="Logo" src="$relpath^$projectlogo"/></td>
-  <!--END PROJECT_LOGO-->
-  <!--BEGIN PROJECT_NAME-->
-  <td id="projectalign">
-   <div id="projectname">$projectname<!--BEGIN PROJECT_NUMBER--><span id="projectnumber">&#160;$projectnumber</span><!--END PROJECT_NUMBER-->
-   </div>
-   <!--BEGIN PROJECT_BRIEF--><div id="projectbrief">$projectbrief</div><!--END PROJECT_BRIEF-->
-  </td>
-  <!--END PROJECT_NAME-->
-  <!--BEGIN !PROJECT_NAME-->
-   <!--BEGIN PROJECT_BRIEF-->
-    <td>
-    <div id="projectbrief">$projectbrief</div>
-    </td>
-   <!--END PROJECT_BRIEF-->
-  <!--END !PROJECT_NAME-->
-  <!--BEGIN DISABLE_INDEX-->
-   <!--BEGIN SEARCHENGINE-->
-     <!--BEGIN !FULL_SIDEBAR-->
-    <td>$searchbox</td>
-     <!--END !FULL_SIDEBAR-->
-   <!--END SEARCHENGINE-->
-  <!--END DISABLE_INDEX-->
- </tr>
-  <!--BEGIN SEARCHENGINE-->
-   <!--BEGIN FULL_SIDEBAR-->
-   <tr><td colspan="2">$searchbox</td></tr>
-   <!--END FULL_SIDEBAR-->
-  <!--END SEARCHENGINE-->
- </tbody>
-</table>
-</div>
-<!--END TITLEAREA-->
-<!-- end header part -->
@@ -1,157 +0,0 @@
-/**
-
-Doxygen Awesome
-https://github.com/jothepro/doxygen-awesome-css
-
-MIT License
-
-Copyright (c) 2021 - 2023 jothepro
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
-
-*/
-
-class DoxygenAwesomeDarkModeToggle extends HTMLElement {
-    // SVG icons from https://fonts.google.com/icons
-    // Licensed under the Apache 2.0 license:
-    // https://www.apache.org/licenses/LICENSE-2.0.html
-    static lightModeIcon = `<svg xmlns="http://www.w3.org/2000/svg" enable-background="new 0 0 24 24" height="24px" viewBox="0 0 24 24" width="24px" fill="#FCBF00"><rect fill="none" height="24" width="24"/><circle cx="12" cy="12" opacity=".3" r="3"/><path d="M12,9c1.65,0,3,1.35,3,3s-1.35,3-3,3s-3-1.35-3-3S10.35,9,12,9 M12,7c-2.76,0-5,2.24-5,5s2.24,5,5,5s5-2.24,5-5 S14.76,7,12,7L12,7z M2,13l2,0c0.55,0,1-0.45,1-1s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S1.45,13,2,13z M20,13l2,0c0.55,0,1-0.45,1-1 s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S19.45,13,20,13z M11,2v2c0,0.55,0.45,1,1,1s1-0.45,1-1V2c0-0.55-0.45-1-1-1S11,1.45,11,2z M11,20v2c0,0.55,0.45,1,1,1s1-0.45,1-1v-2c0-0.55-0.45-1-1-1C11.45,19,11,19.45,11,20z M5.99,4.58c-0.39-0.39-1.03-0.39-1.41,0 c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0s0.39-1.03,0-1.41L5.99,4.58z M18.36,16.95 c-0.39-0.39-1.03-0.39-1.41,0c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0c0.39-0.39,0.39-1.03,0-1.41 L18.36,16.95z M19.42,5.99c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06c-0.39,0.39-0.39,1.03,0,1.41 s1.03,0.39,1.41,0L19.42,5.99z M7.05,18.36c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06 c-0.39,0.39-0.39,1.03,0,1.41s1.03,0.39,1.41,0L7.05,18.36z"/></svg>`
-    static darkModeIcon = `<svg xmlns="http://www.w3.org/2000/svg" enable-background="new 0 0 24 24" height="24px" viewBox="0 0 24 24" width="24px" fill="#FE9700"><rect fill="none" height="24" width="24"/><path d="M9.37,5.51C9.19,6.15,9.1,6.82,9.1,7.5c0,4.08,3.32,7.4,7.4,7.4c0.68,0,1.35-0.09,1.99-0.27 C17.45,17.19,14.93,19,12,19c-3.86,0-7-3.14-7-7C5,9.07,6.81,6.55,9.37,5.51z" opacity=".3"/><path d="M9.37,5.51C9.19,6.15,9.1,6.82,9.1,7.5c0,4.08,3.32,7.4,7.4,7.4c0.68,0,1.35-0.09,1.99-0.27C17.45,17.19,14.93,19,12,19 c-3.86,0-7-3.14-7-7C5,9.07,6.81,6.55,9.37,5.51z M12,3c-4.97,0-9,4.03-9,9s4.03,9,9,9s9-4.03,9-9c0-0.46-0.04-0.92-0.1-1.36 c-0.98,1.37-2.58,2.26-4.4,2.26c-2.98,0-5.4-2.42-5.4-5.4c0-1.81,0.89-3.42,2.26-4.4C12.92,3.04,12.46,3,12,3L12,3z"/></svg>`
-    static title = "Toggle Light/Dark Mode"
-
-    static prefersLightModeInDarkModeKey = "prefers-light-mode-in-dark-mode"
-    static prefersDarkModeInLightModeKey = "prefers-dark-mode-in-light-mode"
-
-    static _staticConstructor = function() {
-        DoxygenAwesomeDarkModeToggle.enableDarkMode(DoxygenAwesomeDarkModeToggle.userPreference)
-        // Update the color scheme when the browsers preference changes
-        // without user interaction on the website.
-        window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', event => {
-            DoxygenAwesomeDarkModeToggle.onSystemPreferenceChanged()
-        })
-        // Update the color scheme when the tab is made visible again.
-        // It is possible that the appearance was changed in another tab 
-        // while this tab was in the background.
-        document.addEventListener("visibilitychange", visibilityState => {
-            if (document.visibilityState === 'visible') {
-                DoxygenAwesomeDarkModeToggle.onSystemPreferenceChanged()
-            }
-        });
-    }()
-
-    static init() {
-        $(function() {
-            $(document).ready(function() {
-                const toggleButton = document.createElement('doxygen-awesome-dark-mode-toggle')
-                toggleButton.title = DoxygenAwesomeDarkModeToggle.title
-                toggleButton.updateIcon()
-
-                window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', event => {
-                    toggleButton.updateIcon()
-                })
-                document.addEventListener("visibilitychange", visibilityState => {
-                    if (document.visibilityState === 'visible') {
-                        toggleButton.updateIcon()
-                    }
-                });
-
-                $(document).ready(function(){
-                    document.getElementById("MSearchBox").parentNode.appendChild(toggleButton)
-                })
-                $(window).resize(function(){
-                    document.getElementById("MSearchBox").parentNode.appendChild(toggleButton)
-                })
-            })
-        })
-    }
-
-    constructor() {
-        super();
-        this.onclick=this.toggleDarkMode
-    }
-
-    /**
-     * @returns `true` for dark-mode, `false` for light-mode system preference
-     */
-    static get systemPreference() {
-        return window.matchMedia('(prefers-color-scheme: dark)').matches
-    }
-
-    /**
-     * @returns `true` for dark-mode, `false` for light-mode user preference
-     */
-    static get userPreference() {
-        return (!DoxygenAwesomeDarkModeToggle.systemPreference && localStorage.getItem(DoxygenAwesomeDarkModeToggle.prefersDarkModeInLightModeKey)) || 
-        (DoxygenAwesomeDarkModeToggle.systemPreference && !localStorage.getItem(DoxygenAwesomeDarkModeToggle.prefersLightModeInDarkModeKey))
-    }
-
-    static set userPreference(userPreference) {
-        DoxygenAwesomeDarkModeToggle.darkModeEnabled = userPreference
-        if(!userPreference) {
-            if(DoxygenAwesomeDarkModeToggle.systemPreference) {
-                localStorage.setItem(DoxygenAwesomeDarkModeToggle.prefersLightModeInDarkModeKey, true)
-            } else {
-                localStorage.removeItem(DoxygenAwesomeDarkModeToggle.prefersDarkModeInLightModeKey)
-            }
-        } else {
-            if(!DoxygenAwesomeDarkModeToggle.systemPreference) {
-                localStorage.setItem(DoxygenAwesomeDarkModeToggle.prefersDarkModeInLightModeKey, true)
-            } else {
-                localStorage.removeItem(DoxygenAwesomeDarkModeToggle.prefersLightModeInDarkModeKey)
-            }
-        }
-        DoxygenAwesomeDarkModeToggle.onUserPreferenceChanged()
-    }
-
-    static enableDarkMode(enable) {
-        if(enable) {
-            DoxygenAwesomeDarkModeToggle.darkModeEnabled = true
-            document.documentElement.classList.add("dark-mode")
-            document.documentElement.classList.remove("light-mode")
-        } else {
-            DoxygenAwesomeDarkModeToggle.darkModeEnabled = false
-            document.documentElement.classList.remove("dark-mode")
-            document.documentElement.classList.add("light-mode")
-        }
-    }
-
-    static onSystemPreferenceChanged() {
-        DoxygenAwesomeDarkModeToggle.darkModeEnabled = DoxygenAwesomeDarkModeToggle.userPreference
-        DoxygenAwesomeDarkModeToggle.enableDarkMode(DoxygenAwesomeDarkModeToggle.darkModeEnabled)
-    }
-
-    static onUserPreferenceChanged() {
-        DoxygenAwesomeDarkModeToggle.enableDarkMode(DoxygenAwesomeDarkModeToggle.darkModeEnabled)
-    }
-
-    toggleDarkMode() {
-        DoxygenAwesomeDarkModeToggle.userPreference = !DoxygenAwesomeDarkModeToggle.userPreference
-        this.updateIcon()
-    }
-
-    updateIcon() {
-        if(DoxygenAwesomeDarkModeToggle.darkModeEnabled) {
-            this.innerHTML = DoxygenAwesomeDarkModeToggle.darkModeIcon
-        } else {
-            this.innerHTML = DoxygenAwesomeDarkModeToggle.lightModeIcon
-        }
-    }
-}
-
-customElements.define("doxygen-awesome-dark-mode-toggle", DoxygenAwesomeDarkModeToggle);
@@ -16,7 +16,7 @@ DOXYGEN_CONF = CodeDocumentation.conf
 # doxygen uses: graphviz, latex
 html: $(DOXYGEN_CONF)
 	@# Generate the html documentation
-	@( cat $(DOXYGEN_CONF) ; printf "$(MFEM_DOXYGEN_FLAGS)\n" ) | doxygen -
+	@( cat $(DOXYGEN_CONF) ; echo "$(MFEM_DOXYGEN_FLAGS)" ) | doxygen -
 	@echo "<meta http-equiv=\"REFRESH\" content=\"0;URL=CodeDocumentation/html/index.html\">" > CodeDocumentation.html
 	@cat warnings.log 1>&2
 	@# Generate the log of undocumented methods
@@ -45,12 +45,6 @@ list(APPEND ALL_EXE_SRCS
  ex37.cpp
  )

-if(MFEM_USE_LAPACK)
-list(APPEND ALL_EXE_SRCS
-  ex38.cpp
-  )
-endif()
-
 if (MFEM_USE_MPI)
  list(APPEND ALL_EXE_SRCS
    ex0p.cpp
@@ -62,7 +62,7 @@ protected:

   BilinearForm M, S;
   NonlinearForm H;
-   real_t viscosity;
+   double viscosity;
   HyperelasticModel *model;

   CGSolver M_solver; // Krylov solver for inverting the mass matrix M
@@ -84,16 +84,16 @@ protected:

 public:
   HyperelasticOperator(FiniteElementSpace &f, Array<int> &ess_bdr,
-                        real_t visc, real_t mu, real_t K);
+                        double visc, double mu, double K);

   /// Compute the right-hand side of the ODE system.
   virtual void Mult(const Vector &vx, Vector &dvx_dt) const;
   /** Solve the Backward-Euler equation: k = f(x + dt*k, t), for the unknown k.
       This is the only requirement for high-order SDIRK implicit integration.*/
-   virtual void ImplicitSolve(const real_t dt, const Vector &x, Vector &k);
+   virtual void ImplicitSolve(const double dt, const Vector &x, Vector &k);

-   real_t ElasticEnergy(const Vector &x) const;
-   real_t KineticEnergy(const Vector &v) const;
+   double ElasticEnergy(const Vector &x) const;
+   double KineticEnergy(const Vector &v) const;
   void GetElasticEnergyDensity(const GridFunction &x, GridFunction &w) const;

   virtual ~HyperelasticOperator();
@@ -109,7 +109,7 @@ private:
   BilinearForm *M, *S;
   NonlinearForm *H;
   mutable SparseMatrix *Jacobian;
-   real_t dt;
+   double dt;
   const Vector *v, *x;
   mutable Vector w, z;

@@ -117,7 +117,7 @@ public:
   ReducedSystemOperator(BilinearForm *M_, BilinearForm *S_, NonlinearForm *H_);

   /// Set current dt, v, x values - needed to compute action and Jacobian.
-   void SetParameters(real_t dt_, const Vector *v_, const Vector *x_);
+   void SetParameters(double dt_, const Vector *v_, const Vector *x_);

   /// Compute y = H(x + dt (v + dt k)) + M k + S (v + dt k).
   virtual void Mult(const Vector &k, Vector &y) const;
@@ -141,7 +141,7 @@ private:
 public:
   ElasticEnergyCoefficient(HyperelasticModel &m, const GridFunction &x_)
      : model(m), x(x_) { }
-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip);
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip);
   virtual ~ElasticEnergyCoefficient() { }
 };

@@ -161,11 +161,11 @@ int main(int argc, char *argv[])
   int ref_levels = 2;
   int order = 2;
   int ode_solver_type = 3;
-   real_t t_final = 300.0;
-   real_t dt = 3.0;
-   real_t visc = 1e-2;
-   real_t mu = 0.25;
-   real_t K = 5.0;
+   double t_final = 300.0;
+   double dt = 3.0;
+   double visc = 1e-2;
+   double mu = 0.25;
+   double K = 5.0;
   bool visualization = true;
   int vis_steps = 1;

@@ -205,10 +205,6 @@ int main(int argc, char *argv[])
   }
   args.PrintOptions(cout);

-#ifdef MFEM_USE_SINGLE
-   MFEM_ABORT("This example is not supported in single precision.");
-#endif
-
   // 2. Read the mesh from the given mesh file. We can handle triangular,
   //    quadrilateral, tetrahedral and hexahedral meshes with the same code.
   Mesh *mesh = new Mesh(mesh_file, 1, 1);
@@ -313,13 +309,13 @@ int main(int argc, char *argv[])
           << " Press space (in the GLVis window) to resume it.\n";
   }

-   real_t ee0 = oper.ElasticEnergy(x.GetTrueVector());
-   real_t ke0 = oper.KineticEnergy(v.GetTrueVector());
+   double ee0 = oper.ElasticEnergy(x.GetTrueVector());
+   double ke0 = oper.KineticEnergy(v.GetTrueVector());
   cout << "initial elastic energy (EE) = " << ee0 << endl;
   cout << "initial kinetic energy (KE) = " << ke0 << endl;
   cout << "initial   total energy (TE) = " << (ee0 + ke0) << endl;

-   real_t t = 0.0;
+   double t = 0.0;
   oper.SetTime(t);
   ode_solver->Init(oper);

@@ -328,7 +324,7 @@ int main(int argc, char *argv[])
   bool last_step = false;
   for (int ti = 1; !last_step; ti++)
   {
-      real_t dt_real = min(dt, t_final - t);
+      double dt_real = min(dt, t_final - t);

      ode_solver->Step(vx, t, dt_real);

@@ -336,8 +332,8 @@ int main(int argc, char *argv[])

      if (last_step || (ti % vis_steps) == 0)
      {
-         real_t ee = oper.ElasticEnergy(x.GetTrueVector());
-         real_t ke = oper.KineticEnergy(v.GetTrueVector());
+         double ee = oper.ElasticEnergy(x.GetTrueVector());
+         double ke = oper.KineticEnergy(v.GetTrueVector());

         cout << "step " << ti << ", t = " << t << ", EE = " << ee << ", KE = "
              << ke << ", ΔTE = " << (ee+ke)-(ee0+ke0) << endl;
@@ -423,7 +419,7 @@ ReducedSystemOperator::ReducedSystemOperator(
     dt(0.0), v(NULL), x(NULL), w(height), z(height)
 { }

-void ReducedSystemOperator::SetParameters(real_t dt_, const Vector *v_,
+void ReducedSystemOperator::SetParameters(double dt_, const Vector *v_,
                                          const Vector *x_)
 {
   dt = dt_;  v = v_;  x = x_;
@@ -457,16 +453,16 @@ ReducedSystemOperator::~ReducedSystemOperator()


 HyperelasticOperator::HyperelasticOperator(FiniteElementSpace &f,
-                                           Array<int> &ess_bdr, real_t visc,
-                                           real_t mu, real_t K)
-   : TimeDependentOperator(2*f.GetTrueVSize(), (real_t) 0.0), fespace(f),
+                                           Array<int> &ess_bdr, double visc,
+                                           double mu, double K)
+   : TimeDependentOperator(2*f.GetTrueVSize(), 0.0), fespace(f),
     M(&fespace), S(&fespace), H(&fespace),
     viscosity(visc), z(height/2)
 {
-   const real_t rel_tol = 1e-8;
+   const double rel_tol = 1e-8;
   const int skip_zero_entries = 0;

-   const real_t ref_density = 1.0; // density in the reference configuration
+   const double ref_density = 1.0; // density in the reference configuration
   ConstantCoefficient rho0(ref_density);
   M.AddDomainIntegrator(new VectorMassIntegrator(rho0));
   M.Assemble(skip_zero_entries);
@@ -537,7 +533,7 @@ void HyperelasticOperator::Mult(const Vector &vx, Vector &dvx_dt) const
   dx_dt = v;
 }

-void HyperelasticOperator::ImplicitSolve(const real_t dt,
+void HyperelasticOperator::ImplicitSolve(const double dt,
                                         const Vector &vx, Vector &dvx_dt)
 {
   int sc = height/2;
@@ -559,12 +555,12 @@ void HyperelasticOperator::ImplicitSolve(const real_t dt,
   add(v, dt, dv_dt, dx_dt);
 }

-real_t HyperelasticOperator::ElasticEnergy(const Vector &x) const
+double HyperelasticOperator::ElasticEnergy(const Vector &x) const
 {
   return H.GetEnergy(x);
 }

-real_t HyperelasticOperator::KineticEnergy(const Vector &v) const
+double HyperelasticOperator::KineticEnergy(const Vector &v) const
 {
   return 0.5*M.InnerProduct(v, v);
 }
@@ -585,7 +581,7 @@ HyperelasticOperator::~HyperelasticOperator()
 }


-real_t ElasticEnergyCoefficient::Eval(ElementTransformation &T,
+double ElasticEnergyCoefficient::Eval(ElementTransformation &T,
                                      const IntegrationPoint &ip)
 {
   model.SetTransformation(T);
@@ -605,7 +601,7 @@ void InitialDeformation(const Vector &x, Vector &y)
 void InitialVelocity(const Vector &x, Vector &v)
 {
   const int dim = x.Size();
-   const real_t s = 0.1/64.;
+   const double s = 0.1/64.;

   v = 0.0;
   v(dim-1) = s*x(0)*x(0)*(8.0-x(0));
@@ -63,7 +63,7 @@ protected:

   ParBilinearForm M, S;
   ParNonlinearForm H;
-   real_t viscosity;
+   double viscosity;
   HyperelasticModel *model;

   HypreParMatrix *Mmat; // Mass matrix from ParallelAssemble()
@@ -86,16 +86,16 @@ protected:

 public:
   HyperelasticOperator(ParFiniteElementSpace &f, Array<int> &ess_bdr,
-                        real_t visc, real_t mu, real_t K);
+                        double visc, double mu, double K);

   /// Compute the right-hand side of the ODE system.
   virtual void Mult(const Vector &vx, Vector &dvx_dt) const;
   /** Solve the Backward-Euler equation: k = f(x + dt*k, t), for the unknown k.
       This is the only requirement for high-order SDIRK implicit integration.*/
-   virtual void ImplicitSolve(const real_t dt, const Vector &x, Vector &k);
+   virtual void ImplicitSolve(const double dt, const Vector &x, Vector &k);

-   real_t ElasticEnergy(const ParGridFunction &x) const;
-   real_t KineticEnergy(const ParGridFunction &v) const;
+   double ElasticEnergy(const ParGridFunction &x) const;
+   double KineticEnergy(const ParGridFunction &v) const;
   void GetElasticEnergyDensity(const ParGridFunction &x,
                                ParGridFunction &w) const;

@@ -112,7 +112,7 @@ private:
   ParBilinearForm *M, *S;
   ParNonlinearForm *H;
   mutable HypreParMatrix *Jacobian;
-   real_t dt;
+   double dt;
   const Vector *v, *x;
   mutable Vector w, z;
   const Array<int> &ess_tdof_list;
@@ -122,7 +122,7 @@ public:
                         ParNonlinearForm *H_, const Array<int> &ess_tdof_list);

   /// Set current dt, v, x values - needed to compute action and Jacobian.
-   void SetParameters(real_t dt_, const Vector *v_, const Vector *x_);
+   void SetParameters(double dt_, const Vector *v_, const Vector *x_);

   /// Compute y = H(x + dt (v + dt k)) + M k + S (v + dt k).
   virtual void Mult(const Vector &k, Vector &y) const;
@@ -146,7 +146,7 @@ private:
 public:
   ElasticEnergyCoefficient(HyperelasticModel &m, const ParGridFunction &x_)
      : model(m), x(x_) { }
-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip);
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip);
   virtual ~ElasticEnergyCoefficient() { }
 };

@@ -173,11 +173,11 @@ int main(int argc, char *argv[])
   int par_ref_levels = 0;
   int order = 2;
   int ode_solver_type = 3;
-   real_t t_final = 300.0;
-   real_t dt = 3.0;
-   real_t visc = 1e-2;
-   real_t mu = 0.25;
-   real_t K = 5.0;
+   double t_final = 300.0;
+   double dt = 3.0;
+   double visc = 1e-2;
+   double mu = 0.25;
+   double K = 5.0;
   bool adaptive_lin_rtol = true;
   bool visualization = true;
   int vis_steps = 1;
@@ -229,10 +229,6 @@ int main(int argc, char *argv[])
      args.PrintOptions(cout);
   }

-#ifdef MFEM_USE_SINGLE
-   MFEM_ABORT("This example is not supported in single precision.");
-#endif
-
   // 3. Read the serial mesh from the given mesh file on all processors. We can
   //    handle triangular, quadrilateral, tetrahedral and hexahedral meshes
   //    with the same code.
@@ -362,8 +358,8 @@ int main(int argc, char *argv[])
      }
   }

-   real_t ee0 = oper.ElasticEnergy(x_gf);
-   real_t ke0 = oper.KineticEnergy(v_gf);
+   double ee0 = oper.ElasticEnergy(x_gf);
+   double ke0 = oper.KineticEnergy(v_gf);
   if (myid == 0)
   {
      cout << "initial elastic energy (EE) = " << ee0 << endl;
@@ -371,7 +367,7 @@ int main(int argc, char *argv[])
      cout << "initial   total energy (TE) = " << (ee0 + ke0) << endl;
   }

-   real_t t = 0.0;
+   double t = 0.0;
   oper.SetTime(t);
   ode_solver->Init(oper);

@@ -380,7 +376,7 @@ int main(int argc, char *argv[])
   bool last_step = false;
   for (int ti = 1; !last_step; ti++)
   {
-      real_t dt_real = min(dt, t_final - t);
+      double dt_real = min(dt, t_final - t);

      ode_solver->Step(vx, t, dt_real);

@@ -390,8 +386,8 @@ int main(int argc, char *argv[])
      {
         v_gf.SetFromTrueVector(); x_gf.SetFromTrueVector();

-         real_t ee = oper.ElasticEnergy(x_gf);
-         real_t ke = oper.KineticEnergy(v_gf);
+         double ee = oper.ElasticEnergy(x_gf);
+         double ke = oper.KineticEnergy(v_gf);

         if (myid == 0)
         {
@@ -489,7 +485,7 @@ ReducedSystemOperator::ReducedSystemOperator(
     ess_tdof_list(ess_tdof_list_)
 { }

-void ReducedSystemOperator::SetParameters(real_t dt_, const Vector *v_,
+void ReducedSystemOperator::SetParameters(double dt_, const Vector *v_,
                                          const Vector *x_)
 {
   dt = dt_;  v = v_;  x = x_;
@@ -527,17 +523,17 @@ ReducedSystemOperator::~ReducedSystemOperator()


 HyperelasticOperator::HyperelasticOperator(ParFiniteElementSpace &f,
-                                           Array<int> &ess_bdr, real_t visc,
-                                           real_t mu, real_t K)
-   : TimeDependentOperator(2*f.TrueVSize(), (real_t) 0.0), fespace(f),
+                                           Array<int> &ess_bdr, double visc,
+                                           double mu, double K)
+   : TimeDependentOperator(2*f.TrueVSize(), 0.0), fespace(f),
     M(&fespace), S(&fespace), H(&fespace),
     viscosity(visc), M_solver(f.GetComm()), newton_solver(f.GetComm()),
     z(height/2)
 {
-   const real_t rel_tol = 1e-8;
+   const double rel_tol = 1e-8;
   const int skip_zero_entries = 0;

-   const real_t ref_density = 1.0; // density in the reference configuration
+   const double ref_density = 1.0; // density in the reference configuration
   ConstantCoefficient rho0(ref_density);
   M.AddDomainIntegrator(new VectorMassIntegrator(rho0));
   M.Assemble(skip_zero_entries);
@@ -611,7 +607,7 @@ void HyperelasticOperator::Mult(const Vector &vx, Vector &dvx_dt) const
   dx_dt = v;
 }

-void HyperelasticOperator::ImplicitSolve(const real_t dt,
+void HyperelasticOperator::ImplicitSolve(const double dt,
                                         const Vector &vx, Vector &dvx_dt)
 {
   int sc = height/2;
@@ -633,17 +629,17 @@ void HyperelasticOperator::ImplicitSolve(const real_t dt,
   add(v, dt, dv_dt, dx_dt);
 }

-real_t HyperelasticOperator::ElasticEnergy(const ParGridFunction &x) const
+double HyperelasticOperator::ElasticEnergy(const ParGridFunction &x) const
 {
   return H.GetEnergy(x);
 }

-real_t HyperelasticOperator::KineticEnergy(const ParGridFunction &v) const
+double HyperelasticOperator::KineticEnergy(const ParGridFunction &v) const
 {
-   real_t loc_energy = 0.5*M.InnerProduct(v, v);
-   real_t energy;
-   MPI_Allreduce(&loc_energy, &energy, 1, MPITypeMap<real_t>::mpi_type,
-                 MPI_SUM, fespace.GetComm());
+   double loc_energy = 0.5*M.InnerProduct(v, v);
+   double energy;
+   MPI_Allreduce(&loc_energy, &energy, 1, MPI_DOUBLE, MPI_SUM,
+                 fespace.GetComm());
   return energy;
 }

@@ -664,7 +660,7 @@ HyperelasticOperator::~HyperelasticOperator()
 }


-real_t ElasticEnergyCoefficient::Eval(ElementTransformation &T,
+double ElasticEnergyCoefficient::Eval(ElementTransformation &T,
                                      const IntegrationPoint &ip)
 {
   model.SetTransformation(T);
@@ -684,7 +680,7 @@ void InitialDeformation(const Vector &x, Vector &y)
 void InitialVelocity(const Vector &x, Vector &v)
 {
   const int dim = x.Size();
-   const real_t s = 0.1/64.;
+   const double s = 0.1/64.;

   v = 0.0;
   v(dim-1) = s*x(0)*x(0)*(8.0-x(0));
@@ -211,7 +211,7 @@ int main(int argc, char *argv[])
   m->AddDomainIntegrator(new MassIntegrator(one));
   m->Assemble();
   // shift the eigenvalue corresponding to eliminated dofs to a large value
-   m->EliminateEssentialBCDiag(ess_bdr, numeric_limits<real_t>::min());
+   m->EliminateEssentialBCDiag(ess_bdr, numeric_limits<double>::min());
   m->Finalize();

   HypreParMatrix *A = a->ParallelAssemble();
@@ -262,13 +262,12 @@ int main(int argc, char *argv[])
 #ifdef MFEM_USE_STRUMPACK
      if (sp_solver)
      {
-         STRUMPACKSolver * strumpack = new STRUMPACKSolver(MPI_COMM_WORLD, argc, argv);
+         STRUMPACKSolver * strumpack = new STRUMPACKSolver(argc, argv, MPI_COMM_WORLD);
         strumpack->SetPrintFactorStatistics(true);
         strumpack->SetPrintSolveStatistics(false);
         strumpack->SetKrylovSolver(strumpack::KrylovSolver::DIRECT);
         strumpack->SetReorderingStrategy(strumpack::ReorderingStrategy::METIS);
-         strumpack->SetMatching(strumpack::MatchingJob::NONE);
-         strumpack->SetCompression(strumpack::CompressionType::NONE);
+         strumpack->DisableMatching();
         strumpack->SetOperator(*Arow);
         strumpack->SetFromCommandLine();
         precond = strumpack;
@@ -300,7 +299,7 @@ int main(int argc, char *argv[])
   // 9. Compute the eigenmodes and extract the array of eigenvalues. Define a
   //    parallel grid function to represent each of the eigenmodes returned by
   //    the solver.
-   Array<real_t> eigenvalues;
+   Array<double> eigenvalues;
   lobpcg->Solve();
   lobpcg->GetEigenvalues(eigenvalues);
   ParGridFunction x(fespace);
@@ -206,7 +206,7 @@ int main(int argc, char *argv[])
   m->AddDomainIntegrator(new VectorMassIntegrator());
   m->Assemble();
   // shift the eigenvalue corresponding to eliminated dofs to a large value
-   m->EliminateEssentialBCDiag(ess_bdr, numeric_limits<real_t>::min());
+   m->EliminateEssentialBCDiag(ess_bdr, numeric_limits<double>::min());
   m->Finalize();
   if (myid == 0)
   {
@@ -247,7 +247,7 @@ int main(int argc, char *argv[])
   // 10. Compute the eigenmodes and extract the array of eigenvalues. Define a
   //     parallel grid function to represent each of the eigenmodes returned by
   //     the solver.
-   Array<real_t> eigenvalues;
+   Array<double> eigenvalues;
   lobpcg->Solve();
   lobpcg->GetEigenvalues(eigenvalues);
   ParGridFunction x(fespace);
@@ -5,7 +5,6 @@
 // Sample runs:  mpirun -np 4 ex13p -m ../data/star.mesh
 //               mpirun -np 4 ex13p -m ../data/square-disc.mesh -o 2 -n 4
 //               mpirun -np 4 ex13p -m ../data/beam-tet.mesh
-//               mpirun -np 4 ex13p -m ../data/beam-tet.mesh -nc -o 2 -rs 1
 //               mpirun -np 4 ex13p -m ../data/beam-hex.mesh
 //               mpirun -np 4 ex13p -m ../data/escher.mesh
 //               mpirun -np 4 ex13p -m ../data/fichera.mesh
@@ -55,7 +54,6 @@ int main(int argc, char *argv[])
   int par_ref_levels = 1;
   int order = 1;
   int nev = 5;
-   bool nc = false;
   bool visualization = 1;
   const char *device_config = "cpu";

@@ -71,9 +69,6 @@ int main(int argc, char *argv[])
                  " isoparametric space.");
   args.AddOption(&nev, "-n", "--num-eigs",
                  "Number of desired eigenmodes.");
-   args.AddOption(&nc, "-nc", "--non-conforming", "-c",
-                  "--conforming",
-                  "Mark the mesh as nonconforming before partitioning.");
   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
                  "--no-visualization",
                  "Enable or disable GLVis visualization.");
@@ -103,10 +98,6 @@ int main(int argc, char *argv[])
   //    and volume meshes with the same code.
   Mesh *mesh = new Mesh(mesh_file, 1, 1);
   int dim = mesh->Dimension();
-   if (nc)
-   {
-      mesh->EnsureNCMesh(true);
-   }

   // 5. Refine the serial mesh on all processors to increase the resolution. In
   //    this example we do 'ref_levels' of uniform refinement (2 by default, or
@@ -170,7 +161,7 @@ int main(int argc, char *argv[])
   m->AddDomainIntegrator(new VectorFEMassIntegrator(one));
   m->Assemble();
   // shift the eigenvalue corresponding to eliminated dofs to a large value
-   m->EliminateEssentialBCDiag(ess_bdr, numeric_limits<real_t>::min());
+   m->EliminateEssentialBCDiag(ess_bdr, numeric_limits<double>::min());
   m->Finalize();

   HypreParMatrix *A = a->ParallelAssemble();
@@ -198,7 +189,7 @@ int main(int argc, char *argv[])
   // 10. Compute the eigenmodes and extract the array of eigenvalues. Define a
   //     parallel grid function to represent each of the eigenmodes returned by
   //     the solver.
-   Array<real_t> eigenvalues;
+   Array<double> eigenvalues;
   ame->Solve();
   ame->GetEigenvalues(eigenvalues);
   ParGridFunction x(fespace);
@@ -43,9 +43,9 @@ int main(int argc, char *argv[])
   const char *mesh_file = "../data/star.mesh";
   int ref_levels = -1;
   int order = 1;
-   real_t sigma = -1.0;
-   real_t kappa = -1.0;
-   real_t eta = 0.0;
+   double sigma = -1.0;
+   double kappa = -1.0;
+   double eta = 0.0;
   bool visualization = 1;

   OptionsParser args(argc, argv);
@@ -44,7 +44,7 @@ public:
      pmesh(m),
      pgf(f) {}

-   void MonitorSolution(int i, real_t norm, const Vector &x, bool final)
+   void MonitorSolution(int i, double norm, const Vector &x, bool final)
   {
      char vishost[] = "localhost";
      int  visport   = 19916;
@@ -81,9 +81,9 @@ int main(int argc, char *argv[])
   int ser_ref_levels = -1;
   int par_ref_levels = 2;
   int order = 1;
-   real_t sigma = -1.0;
-   real_t kappa = -1.0;
-   real_t eta = 0.0;
+   double sigma = -1.0;
+   double kappa = -1.0;
+   double eta = 0.0;
   bool visualization = 1;

   OptionsParser args(argc, argv);
@@ -63,8 +63,8 @@ int problem;
 int nfeatures;

 // Prescribed time-dependent boundary and right-hand side functions.
-real_t bdr_func(const Vector &pt, real_t t);
-real_t rhs_func(const Vector &pt, real_t t);
+double bdr_func(const Vector &pt, double t);
+double rhs_func(const Vector &pt, double t);

 // Update the finite element space, interpolate the solution and perform
 // parallel load balancing.
@@ -79,9 +79,9 @@ int main(int argc, char *argv[])
   nfeatures = 1;
   const char *mesh_file = "../data/star-hilbert.mesh";
   int order = 2;
-   real_t t_final = 1.0;
-   real_t max_elem_error = 5.0e-3;
-   real_t hysteresis = 0.15; // derefinement safety coefficient
+   double t_final = 1.0;
+   double max_elem_error = 5.0e-3;
+   double hysteresis = 0.15; // derefinement safety coefficient
   int ref_levels = 0;
   int nc_limit = 3;         // maximum level of hanging nodes
   bool visualization = true;
@@ -247,7 +247,7 @@ int main(int argc, char *argv[])
   //     refine the mesh as many times as necessary. Then we derefine any
   //     elements which have very small errors.
   x = 0.0;
-   for (real_t time = 0.0; time < t_final + 1e-10; time += 0.01)
+   for (double time = 0.0; time < t_final + 1e-10; time += 0.01)
   {
      cout << "\nTime " << time << "\n\nRefinement:" << endl;

@@ -366,47 +366,47 @@ void UpdateProblem(Mesh &mesh, FiniteElementSpace &fespace,
 }


-const real_t alpha = 0.02;
+const double alpha = 0.02;

 // Spherical front with a Gaussian cross section and radius t
-real_t front(real_t x, real_t y, real_t z, real_t t, int)
+double front(double x, double y, double z, double t, int)
 {
-   real_t r = sqrt(x*x + y*y + z*z);
+   double r = sqrt(x*x + y*y + z*z);
   return exp(-0.5*pow((r - t)/alpha, 2));
 }

-real_t front_laplace(real_t x, real_t y, real_t z, real_t t, int dim)
+double front_laplace(double x, double y, double z, double t, int dim)
 {
-   real_t x2 = x*x, y2 = y*y, z2 = z*z, t2 = t*t;
-   real_t r = sqrt(x2 + y2 + z2);
-   real_t a2 = alpha*alpha, a4 = a2*a2;
+   double x2 = x*x, y2 = y*y, z2 = z*z, t2 = t*t;
+   double r = sqrt(x2 + y2 + z2);
+   double a2 = alpha*alpha, a4 = a2*a2;
   return -exp(-0.5*pow((r - t)/alpha, 2)) / a4 *
          (-2*t*(x2 + y2 + z2 - (dim-1)*a2/2)/r + x2 + y2 + z2 + t2 - dim*a2);
 }

 // Smooth spherical step function with radius t
-real_t ball(real_t x, real_t y, real_t z, real_t t, int)
+double ball(double x, double y, double z, double t, int)
 {
-   real_t r = sqrt(x*x + y*y + z*z);
+   double r = sqrt(x*x + y*y + z*z);
   return -atan(2*(r - t)/alpha);
 }

-real_t ball_laplace(real_t x, real_t y, real_t z, real_t t, int dim)
+double ball_laplace(double x, double y, double z, double t, int dim)
 {
-   real_t x2 = x*x, y2 = y*y, z2 = z*z, t2 = 4*t*t;
-   real_t r = sqrt(x2 + y2 + z2);
-   real_t a2 = alpha*alpha;
-   real_t den = pow(-a2 - 4*(x2 + y2 + z2 - 2*r*t) - t2, 2.0);
+   double x2 = x*x, y2 = y*y, z2 = z*z, t2 = 4*t*t;
+   double r = sqrt(x2 + y2 + z2);
+   double a2 = alpha*alpha;
+   double den = pow(-a2 - 4*(x2 + y2 + z2 - 2*r*t) - t2, 2.0);
   return (dim == 2) ? 2*alpha*(a2 + t2 - 4*x2 - 4*y2)/r/den
          /*      */ : 4*alpha*(a2 + t2 - 4*r*t)/r/den;
 }

 // Composes several features into one function
 template<typename F0, typename F1>
-real_t composite_func(const Vector &pt, real_t t, F0 f0, F1 f1)
+double composite_func(const Vector &pt, double t, F0 f0, F1 f1)
 {
   int dim = pt.Size();
-   real_t x = pt(0), y = pt(1), z = 0.0;
+   double x = pt(0), y = pt(1), z = 0.0;
   if (dim == 3) { z = pt(2); }

   if (problem == 0)
@@ -417,11 +417,11 @@ real_t composite_func(const Vector &pt, real_t t, F0 f0, F1 f1)
      }
      else
      {
-         real_t sum = 0.0;
+         double sum = 0.0;
         for (int i = 0; i < nfeatures; i++)
         {
-            real_t x0 = 0.5*cos(2*M_PI * i / nfeatures);
-            real_t y0 = 0.5*sin(2*M_PI * i / nfeatures);
+            double x0 = 0.5*cos(2*M_PI * i / nfeatures);
+            double y0 = 0.5*sin(2*M_PI * i / nfeatures);
            sum += f0(x - x0, y - y0, z, t, dim);
         }
         return sum;
@@ -429,11 +429,11 @@ real_t composite_func(const Vector &pt, real_t t, F0 f0, F1 f1)
   }
   else
   {
-      real_t sum = 0.0;
+      double sum = 0.0;
      for (int i = 0; i < nfeatures; i++)
      {
-         real_t x0 = 0.5*cos(2*M_PI * i / nfeatures + M_PI*t);
-         real_t y0 = 0.5*sin(2*M_PI * i / nfeatures + M_PI*t);
+         double x0 = 0.5*cos(2*M_PI * i / nfeatures + M_PI*t);
+         double y0 = 0.5*sin(2*M_PI * i / nfeatures + M_PI*t);
         sum += f1(x - x0, y - y0, z, 0.25, dim);
      }
      return sum;
@@ -441,13 +441,13 @@ real_t composite_func(const Vector &pt, real_t t, F0 f0, F1 f1)
 }

 // Exact solution, used for the Dirichlet BC.
-real_t bdr_func(const Vector &pt, real_t t)
+double bdr_func(const Vector &pt, double t)
 {
   return composite_func(pt, t, front, ball);
 }

 // Laplace of the exact solution, used for the right hand side.
-real_t rhs_func(const Vector &pt, real_t t)
+double rhs_func(const Vector &pt, double t)
 {
   return composite_func(pt, t, front_laplace, ball_laplace);
 }
@@ -13,7 +13,6 @@
 //               mpirun -np 4 ex15p -m ../data/square-disc-nurbs.mesh
 //               mpirun -np 4 ex15p -m ../data/disc-nurbs.mesh
 //               mpirun -np 4 ex15p -m ../data/fichera.mesh -tf 0.5
-//               mpirun -np 4 ex15p -m ../data/fichera-mixed.mesh -tf 0.5
 //               mpirun -np 4 ex15p -m ../data/ball-nurbs.mesh -tf 0.5
 //               mpirun -np 4 ex15p -m ../data/mobius-strip.mesh
 //               mpirun -np 4 ex15p -m ../data/amr-quad.mesh
@@ -68,8 +67,8 @@ int problem;
 int nfeatures;

 // Prescribed time-dependent boundary and right-hand side functions.
-real_t bdr_func(const Vector &pt, real_t t);
-real_t rhs_func(const Vector &pt, real_t t);
+double bdr_func(const Vector &pt, double t);
+double rhs_func(const Vector &pt, double t);

 // Update the finite element space, interpolate the solution and perform
 // parallel load balancing.
@@ -91,9 +90,9 @@ int main(int argc, char *argv[])
   nfeatures = 1;
   const char *mesh_file = "../data/star-hilbert.mesh";
   int order = 2;
-   real_t t_final = 1.0;
-   real_t max_elem_error = 1.0e-4;
-   real_t hysteresis = 0.25; // derefinement safety coefficient
+   double t_final = 1.0;
+   double max_elem_error = 1.0e-4;
+   double hysteresis = 0.25; // derefinement safety coefficient
   int ref_levels = 0;
   int nc_limit = 3;         // maximum level of hanging nodes
   bool visualization = true;
@@ -282,7 +281,7 @@ int main(int argc, char *argv[])
   //     solve the problem on the current mesh, visualize the solution and
   //     refine the mesh as many times as necessary. Then we derefine any
   //     elements which have very small errors.
-   for (real_t time = 0.0; time < t_final + 1e-10; time += 0.01)
+   for (double time = 0.0; time < t_final + 1e-10; time += 0.01)
   {
      if (myid == 0)
      {
@@ -427,47 +426,47 @@ void UpdateAndRebalance(ParMesh &pmesh, ParFiniteElementSpace &fespace,
 }


-const real_t alpha = 0.02;
+const double alpha = 0.02;

 // Spherical front with a Gaussian cross section and radius t
-real_t front(real_t x, real_t y, real_t z, real_t t, int)
+double front(double x, double y, double z, double t, int)
 {
-   real_t r = sqrt(x*x + y*y + z*z);
+   double r = sqrt(x*x + y*y + z*z);
   return exp(-0.5*pow((r - t)/alpha, 2));
 }

-real_t front_laplace(real_t x, real_t y, real_t z, real_t t, int dim)
+double front_laplace(double x, double y, double z, double t, int dim)
 {
-   real_t x2 = x*x, y2 = y*y, z2 = z*z, t2 = t*t;
-   real_t r = sqrt(x2 + y2 + z2);
-   real_t a2 = alpha*alpha, a4 = a2*a2;
+   double x2 = x*x, y2 = y*y, z2 = z*z, t2 = t*t;
+   double r = sqrt(x2 + y2 + z2);
+   double a2 = alpha*alpha, a4 = a2*a2;
   return -exp(-0.5*pow((r - t)/alpha, 2)) / a4 *
          (-2*t*(x2 + y2 + z2 - (dim-1)*a2/2)/r + x2 + y2 + z2 + t2 - dim*a2);
 }

 // Smooth spherical step function with radius t
-real_t ball(real_t x, real_t y, real_t z, real_t t, int)
+double ball(double x, double y, double z, double t, int)
 {
-   real_t r = sqrt(x*x + y*y + z*z);
+   double r = sqrt(x*x + y*y + z*z);
   return -atan(2*(r - t)/alpha);
 }

-real_t ball_laplace(real_t x, real_t y, real_t z, real_t t, int dim)
+double ball_laplace(double x, double y, double z, double t, int dim)
 {
-   real_t x2 = x*x, y2 = y*y, z2 = z*z, t2 = 4*t*t;
-   real_t r = sqrt(x2 + y2 + z2);
-   real_t a2 = alpha*alpha;
-   real_t den = pow(-a2 - 4*(x2 + y2 + z2 - 2*r*t) - t2, 2.0);
+   double x2 = x*x, y2 = y*y, z2 = z*z, t2 = 4*t*t;
+   double r = sqrt(x2 + y2 + z2);
+   double a2 = alpha*alpha;
+   double den = pow(-a2 - 4*(x2 + y2 + z2 - 2*r*t) - t2, 2.0);
   return (dim == 2) ? 2*alpha*(a2 + t2 - 4*x2 - 4*y2)/r/den
          /*      */ : 4*alpha*(a2 + t2 - 4*r*t)/r/den;
 }

 // Composes several features into one function
 template<typename F0, typename F1>
-real_t composite_func(const Vector &pt, real_t t, F0 f0, F1 f1)
+double composite_func(const Vector &pt, double t, F0 f0, F1 f1)
 {
   int dim = pt.Size();
-   real_t x = pt(0), y = pt(1), z = 0.0;
+   double x = pt(0), y = pt(1), z = 0.0;
   if (dim == 3) { z = pt(2); }

   if (problem == 0)
@@ -478,11 +477,11 @@ real_t composite_func(const Vector &pt, real_t t, F0 f0, F1 f1)
      }
      else
      {
-         real_t sum = 0.0;
+         double sum = 0.0;
         for (int i = 0; i < nfeatures; i++)
         {
-            real_t x0 = 0.5*cos(2*M_PI * i / nfeatures);
-            real_t y0 = 0.5*sin(2*M_PI * i / nfeatures);
+            double x0 = 0.5*cos(2*M_PI * i / nfeatures);
+            double y0 = 0.5*sin(2*M_PI * i / nfeatures);
            sum += f0(x - x0, y - y0, z, t, dim);
         }
         return sum;
@@ -490,11 +489,11 @@ real_t composite_func(const Vector &pt, real_t t, F0 f0, F1 f1)
   }
   else
   {
-      real_t sum = 0.0;
+      double sum = 0.0;
      for (int i = 0; i < nfeatures; i++)
      {
-         real_t x0 = 0.5*cos(2*M_PI * i / nfeatures + M_PI*t);
-         real_t y0 = 0.5*sin(2*M_PI * i / nfeatures + M_PI*t);
+         double x0 = 0.5*cos(2*M_PI * i / nfeatures + M_PI*t);
+         double y0 = 0.5*sin(2*M_PI * i / nfeatures + M_PI*t);
         sum += f1(x - x0, y - y0, z, 0.25, dim);
      }
      return sum;
@@ -502,13 +501,13 @@ real_t composite_func(const Vector &pt, real_t t, F0 f0, F1 f1)
 }

 // Exact solution, used for the Dirichlet BC.
-real_t bdr_func(const Vector &pt, real_t t)
+double bdr_func(const Vector &pt, double t)
 {
   return composite_func(pt, t, front, ball);
 }

 // Laplace of the exact solution, used for the right hand side.
-real_t rhs_func(const Vector &pt, real_t t)
+double rhs_func(const Vector &pt, double t)
 {
   return composite_func(pt, t, front_laplace, ball_laplace);
 }
@@ -60,7 +60,7 @@ protected:

   SparseMatrix Mmat, Kmat;
   SparseMatrix *T; // T = M + dt K
-   real_t current_dt;
+   double current_dt;

   CGSolver M_solver; // Krylov solver for inverting the mass matrix M
   DSmoother M_prec;  // Preconditioner for the mass matrix M
@@ -68,18 +68,18 @@ protected:
   CGSolver T_solver; // Implicit solver for T = M + dt K
   DSmoother T_prec;  // Preconditioner for the implicit solver

-   real_t alpha, kappa;
+   double alpha, kappa;

   mutable Vector z; // auxiliary vector

 public:
-   ConductionOperator(FiniteElementSpace &f, real_t alpha, real_t kappa,
+   ConductionOperator(FiniteElementSpace &f, double alpha, double kappa,
                      const Vector &u);

   virtual void Mult(const Vector &u, Vector &du_dt) const;
   /** Solve the Backward-Euler equation: k = f(u + dt*k, t), for the unknown k.
       This is the only requirement for high-order SDIRK implicit integration.*/
-   virtual void ImplicitSolve(const real_t dt, const Vector &u, Vector &k);
+   virtual void ImplicitSolve(const double dt, const Vector &u, Vector &k);

   /// Update the diffusion BilinearForm K using the given true-dof vector `u`.
   void SetParameters(const Vector &u);
@@ -87,7 +87,7 @@ public:
   virtual ~ConductionOperator();
 };

-real_t InitialTemperature(const Vector &x);
+double InitialTemperature(const Vector &x);

 int main(int argc, char *argv[])
 {
@@ -96,10 +96,10 @@ int main(int argc, char *argv[])
   int ref_levels = 2;
   int order = 2;
   int ode_solver_type = 3;
-   real_t t_final = 0.5;
-   real_t dt = 1.0e-2;
-   real_t alpha = 1.0e-2;
-   real_t kappa = 0.5;
+   double t_final = 0.5;
+   double dt = 1.0e-2;
+   double alpha = 1.0e-2;
+   double kappa = 0.5;
   bool visualization = true;
   bool visit = false;
   int vis_steps = 5;
@@ -246,7 +246,7 @@ int main(int argc, char *argv[])
   // 8. Perform time-integration (looping over the time iterations, ti, with a
   //    time-step dt).
   ode_solver->Init(oper);
-   real_t t = 0.0;
+   double t = 0.0;

   bool last_step = false;
   for (int ti = 1; !last_step; ti++)
@@ -293,12 +293,12 @@ int main(int argc, char *argv[])
   return 0;
 }

-ConductionOperator::ConductionOperator(FiniteElementSpace &f, real_t al,
-                                       real_t kap, const Vector &u)
-   : TimeDependentOperator(f.GetTrueVSize(), (real_t) 0.0), fespace(f),
-     M(NULL), K(NULL), T(NULL), current_dt(0.0), z(height)
+ConductionOperator::ConductionOperator(FiniteElementSpace &f, double al,
+                                       double kap, const Vector &u)
+   : TimeDependentOperator(f.GetTrueVSize(), 0.0), fespace(f), M(NULL), K(NULL),
+     T(NULL), current_dt(0.0), z(height)
 {
-   const real_t rel_tol = 1e-8;
+   const double rel_tol = 1e-8;

   M = new BilinearForm(&fespace);
   M->AddDomainIntegrator(new MassIntegrator());
@@ -336,7 +336,7 @@ void ConductionOperator::Mult(const Vector &u, Vector &du_dt) const
   M_solver.Mult(z, du_dt);
 }

-void ConductionOperator::ImplicitSolve(const real_t dt,
+void ConductionOperator::ImplicitSolve(const double dt,
                                       const Vector &u, Vector &du_dt)
 {
   // Solve the equation:
@@ -382,7 +382,7 @@ ConductionOperator::~ConductionOperator()
   delete K;
 }

-real_t InitialTemperature(const Vector &x)
+double InitialTemperature(const Vector &x)
 {
   if (x.Norml2() < 0.5)
   {
@@ -62,7 +62,7 @@ protected:
   HypreParMatrix Mmat;
   HypreParMatrix Kmat;
   HypreParMatrix *T; // T = M + dt K
-   real_t current_dt;
+   double current_dt;

   CGSolver M_solver;    // Krylov solver for inverting the mass matrix M
   HypreSmoother M_prec; // Preconditioner for the mass matrix M
@@ -70,18 +70,18 @@ protected:
   CGSolver T_solver;    // Implicit solver for T = M + dt K
   HypreSmoother T_prec; // Preconditioner for the implicit solver

-   real_t alpha, kappa;
+   double alpha, kappa;

   mutable Vector z; // auxiliary vector

 public:
-   ConductionOperator(ParFiniteElementSpace &f, real_t alpha, real_t kappa,
+   ConductionOperator(ParFiniteElementSpace &f, double alpha, double kappa,
                      const Vector &u);

   virtual void Mult(const Vector &u, Vector &du_dt) const;
   /** Solve the Backward-Euler equation: k = f(u + dt*k, t), for the unknown k.
       This is the only requirement for high-order SDIRK implicit integration.*/
-   virtual void ImplicitSolve(const real_t dt, const Vector &u, Vector &k);
+   virtual void ImplicitSolve(const double dt, const Vector &u, Vector &k);

   /// Update the diffusion BilinearForm K using the given true-dof vector `u`.
   void SetParameters(const Vector &u);
@@ -89,7 +89,7 @@ public:
   virtual ~ConductionOperator();
 };

-real_t InitialTemperature(const Vector &x);
+double InitialTemperature(const Vector &x);

 int main(int argc, char *argv[])
 {
@@ -105,10 +105,10 @@ int main(int argc, char *argv[])
   int par_ref_levels = 1;
   int order = 2;
   int ode_solver_type = 3;
-   real_t t_final = 0.5;
-   real_t dt = 1.0e-2;
-   real_t alpha = 1.0e-2;
-   real_t kappa = 0.5;
+   double t_final = 0.5;
+   double dt = 1.0e-2;
+   double alpha = 1.0e-2;
+   double kappa = 0.5;
   bool visualization = true;
   bool visit = false;
   int vis_steps = 5;
@@ -313,7 +313,7 @@ int main(int argc, char *argv[])
   // 10. Perform time-integration (looping over the time iterations, ti, with a
   //     time-step dt).
   ode_solver->Init(oper);
-   real_t t = 0.0;
+   double t = 0.0;

   bool last_step = false;
   for (int ti = 1; !last_step; ti++)
@@ -382,13 +382,13 @@ int main(int argc, char *argv[])
   return 0;
 }

-ConductionOperator::ConductionOperator(ParFiniteElementSpace &f, real_t al,
-                                       real_t kap, const Vector &u)
-   : TimeDependentOperator(f.GetTrueVSize(), (real_t) 0.0), fespace(f),
-     M(NULL), K(NULL), T(NULL), current_dt(0.0),
+ConductionOperator::ConductionOperator(ParFiniteElementSpace &f, double al,
+                                       double kap, const Vector &u)
+   : TimeDependentOperator(f.GetTrueVSize(), 0.0), fespace(f), M(NULL), K(NULL),
+     T(NULL), current_dt(0.0),
     M_solver(f.GetComm()), T_solver(f.GetComm()), z(height)
 {
-   const real_t rel_tol = 1e-8;
+   const double rel_tol = 1e-8;

   M = new ParBilinearForm(&fespace);
   M->AddDomainIntegrator(new MassIntegrator());
@@ -427,7 +427,7 @@ void ConductionOperator::Mult(const Vector &u, Vector &du_dt) const
   M_solver.Mult(z, du_dt);
 }

-void ConductionOperator::ImplicitSolve(const real_t dt,
+void ConductionOperator::ImplicitSolve(const double dt,
                                       const Vector &u, Vector &du_dt)
 {
   // Solve the equation:
@@ -473,7 +473,7 @@ ConductionOperator::~ConductionOperator()
   delete K;
 }

-real_t InitialTemperature(const Vector &x)
+double InitialTemperature(const Vector &x)
 {
   if (x.Norml2() < 0.5)
   {
@@ -69,7 +69,7 @@ public:
   void SetDisplacement(GridFunction &u_) { u = &u_; }
   void SetComponent(int i, int j) { si = i; sj = j; }

-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip);
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip);
 };

 // Simple GLVis visualization manager.
@@ -104,8 +104,8 @@ int main(int argc, char *argv[])
   const char *mesh_file = "../data/beam-tri.mesh";
   int ref_levels = -1;
   int order = 1;
-   real_t alpha = -1.0;
-   real_t kappa = -1.0;
+   double alpha = -1.0;
+   double kappa = -1.0;
   bool visualization = 1;

   OptionsParser args(argc, argv);
@@ -245,7 +245,7 @@ int main(int argc, char *argv[])
   //     solve the system Ax=b with PCG for the symmetric formulation, or GMRES
   //     for the non-symmetric.
   GSSmoother M(A);
-   const real_t rtol = 1e-6;
+   const double rtol = 1e-6;
   if (alpha == -1.0)
   {
      PCG(A, M, B, X, 3, 5000, rtol*rtol, 0.0);
@@ -337,17 +337,17 @@ void InitDisplacement(const Vector &x, Vector &u)
 }


-real_t StressCoefficient::Eval(ElementTransformation &T,
+double StressCoefficient::Eval(ElementTransformation &T,
                               const IntegrationPoint &ip)
 {
   MFEM_ASSERT(u != NULL, "displacement field is not set");

-   real_t L = lambda.Eval(T, ip);
-   real_t M = mu.Eval(T, ip);
+   double L = lambda.Eval(T, ip);
+   double M = mu.Eval(T, ip);
   u->GetVectorGradient(T, grad);
   if (si == sj)
   {
-      real_t div_u = grad.Trace();
+      double div_u = grad.Trace();
      return L*div_u + 2*M*grad(si,si);
   }
   else
@@ -69,7 +69,7 @@ public:
   void SetDisplacement(GridFunction &u_) { u = &u_; }
   void SetComponent(int i, int j) { si = i; sj = j; }

-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip);
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip);
 };

 // Simple GLVis visualization manager.
@@ -108,8 +108,8 @@ int main(int argc, char *argv[])
   int ser_ref_levels = -1;
   int par_ref_levels = 1;
   int order = 1;
-   real_t alpha = -1.0;
-   real_t kappa = -1.0;
+   double alpha = -1.0;
+   double kappa = -1.0;
   bool amg_elast = false;
   bool visualization = 1;

@@ -268,7 +268,7 @@ int main(int argc, char *argv[])
   // 11. Define a simple symmetric Gauss-Seidel preconditioner and use it to
   //     solve the system Ax=b with PCG for the symmetric formulation, or GMRES
   //     for the non-symmetric.
-   const real_t rtol = 1e-6;
+   const double rtol = 1e-6;
   HypreBoomerAMG amg(A);
   if (amg_elast)
   {
@@ -376,17 +376,17 @@ void InitDisplacement(const Vector &x, Vector &u)
 }


-real_t StressCoefficient::Eval(ElementTransformation &T,
+double StressCoefficient::Eval(ElementTransformation &T,
                               const IntegrationPoint &ip)
 {
   MFEM_ASSERT(u != NULL, "displacement field is not set");

-   real_t L = lambda.Eval(T, ip);
-   real_t M = mu.Eval(T, ip);
+   double L = lambda.Eval(T, ip);
+   double M = mu.Eval(T, ip);
   u->GetVectorGradient(T, grad);
   if (si == sj)
   {
-      real_t div_u = grad.Trace();
+      double div_u = grad.Trace();
      return L*div_u + 2*M*grad(si,si);
   }
   else
@@ -52,11 +52,11 @@ int problem;

 // Equation constant parameters.
 const int num_equation = 4;
-const real_t specific_heat_ratio = 1.4;
-const real_t gas_constant = 1.0;
+const double specific_heat_ratio = 1.4;
+const double gas_constant = 1.0;

 // Maximum characteristic speed (updated by integrators)
-real_t max_char_speed;
+double max_char_speed;

 int main(int argc, char *argv[])
 {
@@ -66,9 +66,9 @@ int main(int argc, char *argv[])
   int ref_levels = 1;
   int order = 3;
   int ode_solver_type = 4;
-   real_t t_final = 2.0;
-   real_t dt = -0.01;
-   real_t cfl = 0.3;
+   double t_final = 2.0;
+   double dt = -0.01;
+   double cfl = 0.3;
   bool visualization = true;
   int vis_steps = 50;

@@ -228,7 +228,7 @@ int main(int argc, char *argv[])
   }

   // Determine the minimum element size.
-   real_t hmin = 0.0;
+   double hmin = 0.0;
   if (cfl > 0)
   {
      hmin = mesh.GetElementSize(0, 1);
@@ -242,7 +242,7 @@ int main(int argc, char *argv[])
   tic_toc.Clear();
   tic_toc.Start();

-   real_t t = 0.0;
+   double t = 0.0;
   euler.SetTime(t);
   ode_solver->Init(euler);

@@ -260,7 +260,7 @@ int main(int argc, char *argv[])
   bool done = false;
   for (int ti = 0; !done; )
   {
-      real_t dt_real = min(dt, t_final - t);
+      double dt_real = min(dt, t_final - t);

      ode_solver->Step(sol, t, dt_real);
      if (cfl > 0)
@@ -298,7 +298,7 @@ int main(int argc, char *argv[])
   // 10. Compute the L2 solution error summed for all components.
   if (t_final == 2.0)
   {
-      const real_t error = sol.ComputeLpError(2, u0);
+      const double error = sol.ComputeLpError(2, u0);
      cout << "Solution error: " << error << endl;
   }

@@ -9,11 +9,11 @@ using namespace mfem;
 extern int problem;

 // Maximum characteristic speed (updated by integrators)
-extern real_t max_char_speed;
+extern double max_char_speed;

 extern const int num_equation;
-extern const real_t specific_heat_ratio;
-extern const real_t gas_constant;
+extern const double specific_heat_ratio;
+extern const double gas_constant;

 // Time-dependent operator for the right-hand side of the ODE representing the
 // DG weak form.
@@ -52,7 +52,7 @@ private:

 public:
   RiemannSolver();
-   real_t Eval(const Vector &state1, const Vector &state2,
+   double Eval(const Vector &state1, const Vector &state2,
               const Vector &nor, Vector &flux);
 };

@@ -149,13 +149,13 @@ void FE_Evolution::Mult(const Vector &x, Vector &y) const
 bool StateIsPhysical(const Vector &state, const int dim);

 // Pressure (EOS) computation
-inline real_t ComputePressure(const Vector &state, int dim)
+inline double ComputePressure(const Vector &state, int dim)
 {
-   const real_t den = state(0);
+   const double den = state(0);
   const Vector den_vel(state.GetData() + 1, dim);
-   const real_t den_energy = state(1 + dim);
+   const double den_energy = state(1 + dim);

-   real_t den_vel2 = 0;
+   double den_vel2 = 0;
   for (int d = 0; d < dim; d++) { den_vel2 += den_vel(d) * den_vel(d); }
   den_vel2 /= den;

@@ -165,13 +165,13 @@ inline real_t ComputePressure(const Vector &state, int dim)
 // Compute the vector flux F(u)
 void ComputeFlux(const Vector &state, int dim, DenseMatrix &flux)
 {
-   const real_t den = state(0);
+   const double den = state(0);
   const Vector den_vel(state.GetData() + 1, dim);
-   const real_t den_energy = state(1 + dim);
+   const double den_energy = state(1 + dim);

   MFEM_ASSERT(StateIsPhysical(state, dim), "");

-   const real_t pres = ComputePressure(state, dim);
+   const double pres = ComputePressure(state, dim);

   for (int d = 0; d < dim; d++)
   {
@@ -183,7 +183,7 @@ void ComputeFlux(const Vector &state, int dim, DenseMatrix &flux)
      flux(1+d, d) += pres;
   }

-   const real_t H = (den_energy + pres) / den;
+   const double H = (den_energy + pres) / den;
   for (int d = 0; d < dim; d++)
   {
      flux(1+dim, d) = den_vel(d) * H;
@@ -196,15 +196,15 @@ void ComputeFluxDotN(const Vector &state, const Vector &nor,
 {
   // NOTE: nor in general is not a unit normal
   const int dim = nor.Size();
-   const real_t den = state(0);
+   const double den = state(0);
   const Vector den_vel(state.GetData() + 1, dim);
-   const real_t den_energy = state(1 + dim);
+   const double den_energy = state(1 + dim);

   MFEM_ASSERT(StateIsPhysical(state, dim), "");

-   const real_t pres = ComputePressure(state, dim);
+   const double pres = ComputePressure(state, dim);

-   real_t den_velN = 0;
+   double den_velN = 0;
   for (int d = 0; d < dim; d++) { den_velN += den_vel(d) * nor(d); }

   fluxN(0) = den_velN;
@@ -213,23 +213,23 @@ void ComputeFluxDotN(const Vector &state, const Vector &nor,
      fluxN(1+d) = den_velN * den_vel(d) / den + pres * nor(d);
   }

-   const real_t H = (den_energy + pres) / den;
+   const double H = (den_energy + pres) / den;
   fluxN(1 + dim) = den_velN * H;
 }

 // Compute the maximum characteristic speed.
-inline real_t ComputeMaxCharSpeed(const Vector &state, const int dim)
+inline double ComputeMaxCharSpeed(const Vector &state, const int dim)
 {
-   const real_t den = state(0);
+   const double den = state(0);
   const Vector den_vel(state.GetData() + 1, dim);

-   real_t den_vel2 = 0;
+   double den_vel2 = 0;
   for (int d = 0; d < dim; d++) { den_vel2 += den_vel(d) * den_vel(d); }
   den_vel2 /= den;

-   const real_t pres = ComputePressure(state, dim);
-   const real_t sound = sqrt(specific_heat_ratio * pres / den);
-   const real_t vel = sqrt(den_vel2 / den);
+   const double pres = ComputePressure(state, dim);
+   const double sound = sqrt(specific_heat_ratio * pres / den);
+   const double vel = sqrt(den_vel2 / den);

   return vel + sound;
 }
@@ -254,7 +254,7 @@ void FE_Evolution::GetFlux(const DenseMatrix &x_, DenseTensor &flux_) const
      }

      // Update max char speed
-      const real_t mcs = ComputeMaxCharSpeed(state, flux_dim);
+      const double mcs = ComputeMaxCharSpeed(state, flux_dim);
      if (mcs > max_char_speed) { max_char_speed = mcs; }
   }
 }
@@ -264,7 +264,7 @@ RiemannSolver::RiemannSolver() :
   flux1(num_equation),
   flux2(num_equation) { }

-real_t RiemannSolver::Eval(const Vector &state1, const Vector &state2,
+double RiemannSolver::Eval(const Vector &state1, const Vector &state2,
                           const Vector &nor, Vector &flux)
 {
   // NOTE: nor in general is not a unit normal
@@ -273,15 +273,15 @@ real_t RiemannSolver::Eval(const Vector &state1, const Vector &state2,
   MFEM_ASSERT(StateIsPhysical(state1, dim), "");
   MFEM_ASSERT(StateIsPhysical(state2, dim), "");

-   const real_t maxE1 = ComputeMaxCharSpeed(state1, dim);
-   const real_t maxE2 = ComputeMaxCharSpeed(state2, dim);
+   const double maxE1 = ComputeMaxCharSpeed(state1, dim);
+   const double maxE2 = ComputeMaxCharSpeed(state2, dim);

-   const real_t maxE = max(maxE1, maxE2);
+   const double maxE = max(maxE1, maxE2);

   ComputeFluxDotN(state1, nor, flux1);
   ComputeFluxDotN(state2, nor, flux2);

-   real_t normag = 0;
+   double normag = 0;
   for (int i = 0; i < dim; i++)
   {
      normag += nor(i) * nor(i);
@@ -359,7 +359,7 @@ void FaceIntegrator::AssembleFaceVector(const FiniteElement &el1,

      // Get the normal vector and the flux on the face
      CalcOrtho(Tr.Jacobian(), nor);
-      const real_t mcs = rsolver.Eval(funval1, funval2, nor, fluxN);
+      const double mcs = rsolver.Eval(funval1, funval2, nor, fluxN);

      // Update max char speed
      if (mcs > max_char_speed) { max_char_speed = mcs; }
@@ -382,9 +382,9 @@ void FaceIntegrator::AssembleFaceVector(const FiniteElement &el1,
 // Check that the state is physical - enabled in debug mode
 bool StateIsPhysical(const Vector &state, const int dim)
 {
-   const real_t den = state(0);
+   const double den = state(0);
   const Vector den_vel(state.GetData() + 1, dim);
-   const real_t den_energy = state(1 + dim);
+   const double den_energy = state(1 + dim);

   if (den < 0)
   {
@@ -407,11 +407,11 @@ bool StateIsPhysical(const Vector &state, const int dim)
      return false;
   }

-   real_t den_vel2 = 0;
+   double den_vel2 = 0;
   for (int i = 0; i < dim; i++) { den_vel2 += den_vel(i) * den_vel(i); }
   den_vel2 /= den;

-   const real_t pres = (specific_heat_ratio - 1.0) * (den_energy - 0.5 * den_vel2);
+   const double pres = (specific_heat_ratio - 1.0) * (den_energy - 0.5 * den_vel2);

   if (pres <= 0)
   {
@@ -431,7 +431,7 @@ void InitialCondition(const Vector &x, Vector &y)
 {
   MFEM_ASSERT(x.Size() == 2, "");

-   real_t radius = 0, Minf = 0, beta = 0;
+   double radius = 0, Minf = 0, beta = 0;
   if (problem == 1)
   {
      // "Fast vortex"
@@ -452,36 +452,36 @@ void InitialCondition(const Vector &x, Vector &y)
                 "Options are: 1 - fast vortex, 2 - slow vortex");
   }

-   const real_t xc = 0.0, yc = 0.0;
+   const double xc = 0.0, yc = 0.0;

   // Nice units
-   const real_t vel_inf = 1.;
-   const real_t den_inf = 1.;
+   const double vel_inf = 1.;
+   const double den_inf = 1.;

   // Derive remainder of background state from this and Minf
-   const real_t pres_inf = (den_inf / specific_heat_ratio) * (vel_inf / Minf) *
+   const double pres_inf = (den_inf / specific_heat_ratio) * (vel_inf / Minf) *
                           (vel_inf / Minf);
-   const real_t temp_inf = pres_inf / (den_inf * gas_constant);
+   const double temp_inf = pres_inf / (den_inf * gas_constant);

-   real_t r2rad = 0.0;
+   double r2rad = 0.0;
   r2rad += (x(0) - xc) * (x(0) - xc);
   r2rad += (x(1) - yc) * (x(1) - yc);
   r2rad /= (radius * radius);

-   const real_t shrinv1 = 1.0 / (specific_heat_ratio - 1.);
+   const double shrinv1 = 1.0 / (specific_heat_ratio - 1.);

-   const real_t velX = vel_inf * (1 - beta * (x(1) - yc) / radius * exp(
+   const double velX = vel_inf * (1 - beta * (x(1) - yc) / radius * exp(
                                     -0.5 * r2rad));
-   const real_t velY = vel_inf * beta * (x(0) - xc) / radius * exp(-0.5 * r2rad);
-   const real_t vel2 = velX * velX + velY * velY;
+   const double velY = vel_inf * beta * (x(0) - xc) / radius * exp(-0.5 * r2rad);
+   const double vel2 = velX * velX + velY * velY;

-   const real_t specific_heat = gas_constant * specific_heat_ratio * shrinv1;
-   const real_t temp = temp_inf - 0.5 * (vel_inf * beta) *
+   const double specific_heat = gas_constant * specific_heat_ratio * shrinv1;
+   const double temp = temp_inf - 0.5 * (vel_inf * beta) *
                       (vel_inf * beta) / specific_heat * exp(-r2rad);

-   const real_t den = den_inf * pow(temp/temp_inf, shrinv1);
-   const real_t pres = den * gas_constant * temp;
-   const real_t energy = shrinv1 * pres / den + 0.5 * vel2;
+   const double den = den_inf * pow(temp/temp_inf, shrinv1);
+   const double pres = den * gas_constant * temp;
+   const double energy = shrinv1 * pres / den + 0.5 * vel2;

   y(0) = den;
   y(1) = den * velX;
@@ -52,11 +52,11 @@ int problem;

 // Equation constant parameters.
 const int num_equation = 4;
-const real_t specific_heat_ratio = 1.4;
-const real_t gas_constant = 1.0;
+const double specific_heat_ratio = 1.4;
+const double gas_constant = 1.0;

 // Maximum characteristic speed (updated by integrators)
-real_t max_char_speed;
+double max_char_speed;

 int main(int argc, char *argv[])
 {
@@ -71,9 +71,9 @@ int main(int argc, char *argv[])
   int par_ref_levels = 1;
   int order = 3;
   int ode_solver_type = 4;
-   real_t t_final = 2.0;
-   real_t dt = -0.01;
-   real_t cfl = 0.3;
+   double t_final = 2.0;
+   double dt = -0.01;
+   double cfl = 0.3;
   bool visualization = true;
   int vis_steps = 50;

@@ -270,24 +270,23 @@ int main(int argc, char *argv[])
   }

   // Determine the minimum element size.
-   real_t hmin;
+   double hmin;
   if (cfl > 0)
   {
-      real_t my_hmin = pmesh.GetElementSize(0, 1);
+      double my_hmin = pmesh.GetElementSize(0, 1);
      for (int i = 1; i < pmesh.GetNE(); i++)
      {
         my_hmin = min(pmesh.GetElementSize(i, 1), my_hmin);
      }
      // Reduce to find the global minimum element size
-      MPI_Allreduce(&my_hmin, &hmin, 1, MPITypeMap<real_t>::mpi_type,
-                    MPI_MIN, pmesh.GetComm());
+      MPI_Allreduce(&my_hmin, &hmin, 1, MPI_DOUBLE, MPI_MIN, pmesh.GetComm());
   }

   // Start the timer.
   tic_toc.Clear();
   tic_toc.Start();

-   real_t t = 0.0;
+   double t = 0.0;
   euler.SetTime(t);
   ode_solver->Init(euler);

@@ -300,9 +299,9 @@ int main(int argc, char *argv[])
      A.Mult(sol, z);
      // Reduce to find the global maximum wave speed
      {
-         real_t all_max_char_speed;
-         MPI_Allreduce(&max_char_speed, &all_max_char_speed, 1,
-                       MPITypeMap<real_t>::mpi_type, MPI_MAX, pmesh.GetComm());
+         double all_max_char_speed;
+         MPI_Allreduce(&max_char_speed, &all_max_char_speed,
+                       1, MPI_DOUBLE, MPI_MAX, pmesh.GetComm());
         max_char_speed = all_max_char_speed;
      }
      dt = cfl * hmin / max_char_speed / (2*order+1);
@@ -312,16 +311,16 @@ int main(int argc, char *argv[])
   bool done = false;
   for (int ti = 0; !done; )
   {
-      real_t dt_real = min(dt, t_final - t);
+      double dt_real = min(dt, t_final - t);

      ode_solver->Step(sol, t, dt_real);
      if (cfl > 0)
      {
         // Reduce to find the global maximum wave speed
         {
-            real_t all_max_char_speed;
-            MPI_Allreduce(&max_char_speed, &all_max_char_speed, 1,
-                          MPITypeMap<real_t>::mpi_type, MPI_MAX, pmesh.GetComm());
+            double all_max_char_speed;
+            MPI_Allreduce(&max_char_speed, &all_max_char_speed,
+                          1, MPI_DOUBLE, MPI_MAX, pmesh.GetComm());
            max_char_speed = all_max_char_speed;
         }
         dt = cfl * hmin / max_char_speed / (2*order+1);
@@ -367,7 +366,7 @@ int main(int argc, char *argv[])
   // 12. Compute the L2 solution error summed for all components.
   if (t_final == 2.0)
   {
-      const real_t error = sol.ComputeLpError(2, u0);
+      const double error = sol.ComputeLpError(2, u0);
      if (Mpi::Root())
      {
         cout << "Solution error: " << error << endl;
@@ -48,15 +48,15 @@ public:
      print_level = print_lvl;
   }

-   virtual void MonitorResidual(int it, real_t norm, const Vector &r, bool final);
+   virtual void MonitorResidual(int it, double norm, const Vector &r, bool final);

 private:
   const std::string prefix;
   int print_level;
-   mutable real_t norm0;
+   mutable double norm0;
 };

-void GeneralResidualMonitor::MonitorResidual(int it, real_t norm,
+void GeneralResidualMonitor::MonitorResidual(int it, double norm,
                                             const Vector &r, bool final)
 {
   if (print_level == 1 || (print_level == 3 && (final || it == 0)))
@@ -103,7 +103,7 @@ protected:
   BlockOperator *jacobian;

   // Scaling factor for the pressure mass matrix in the block preconditioner
-   real_t gamma;
+   double gamma;

   // Objects for the block preconditioner application
   SparseMatrix *pressure_mass;
@@ -157,7 +157,7 @@ protected:

 public:
   RubberOperator(Array<FiniteElementSpace *> &fes, Array<Array<int> *>&ess_bdr,
-                  Array<int> &block_trueOffsets, real_t rel_tol, real_t abs_tol,
+                  Array<int> &block_trueOffsets, double rel_tol, double abs_tol,
                  int iter, Coefficient &mu);

   // Required to use the native newton solver
@@ -187,10 +187,10 @@ int main(int argc, char *argv[])
   int ref_levels = 0;
   int order = 2;
   bool visualization = true;
-   real_t newton_rel_tol = 1e-4;
-   real_t newton_abs_tol = 1e-6;
+   double newton_rel_tol = 1e-4;
+   double newton_abs_tol = 1e-6;
   int newton_iter = 500;
-   real_t mu = 1.0;
+   double mu = 1.0;

   OptionsParser args(argc, argv);
   args.AddOption(&mesh_file, "-m", "--mesh",
@@ -449,8 +449,8 @@ JacobianPreconditioner::~JacobianPreconditioner()
 RubberOperator::RubberOperator(Array<FiniteElementSpace *> &fes,
                               Array<Array<int> *> &ess_bdr,
                               Array<int> &offsets,
-                               real_t rel_tol,
-                               real_t abs_tol,
+                               double rel_tol,
+                               double abs_tol,
                               int iter,
                               Coefficient &c_mu)
   : Operator(fes[0]->GetTrueVSize() + fes[1]->GetTrueVSize()),
@@ -62,15 +62,15 @@ public:
 #endif
   }

-   virtual void MonitorResidual(int it, real_t norm, const Vector &r, bool final);
+   virtual void MonitorResidual(int it, double norm, const Vector &r, bool final);

 private:
   const std::string prefix;
   int print_level;
-   mutable real_t norm0;
+   mutable double norm0;
 };

-void GeneralResidualMonitor::MonitorResidual(int it, real_t norm,
+void GeneralResidualMonitor::MonitorResidual(int it, double norm,
                                             const Vector &r, bool final)
 {
   if (print_level == 1 || (print_level == 3 && (final || it == 0)))
@@ -117,7 +117,7 @@ protected:
   BlockOperator *jacobian;

   // Scaling factor for the pressure mass matrix in the block preconditioner
-   real_t gamma;
+   double gamma;

   // Objects for the block preconditioner application
   Operator *pressure_mass;
@@ -171,7 +171,7 @@ protected:

 public:
   RubberOperator(Array<ParFiniteElementSpace *> &fes, Array<Array<int> *>&ess_bdr,
-                  Array<int> &block_trueOffsets, real_t rel_tol, real_t abs_tol,
+                  Array<int> &block_trueOffsets, double rel_tol, double abs_tol,
                  int iter, Coefficient &mu);

   // Required to use the native newton solver
@@ -214,10 +214,10 @@ int main(int argc, char *argv[])
   int par_ref_levels = 0;
   int order = 2;
   bool visualization = true;
-   real_t newton_rel_tol = 1e-4;
-   real_t newton_abs_tol = 1e-6;
+   double newton_rel_tol = 1e-4;
+   double newton_abs_tol = 1e-6;
   int newton_iter = 500;
-   real_t mu = 1.0;
+   double mu = 1.0;

   OptionsParser args(argc, argv);
   args.AddOption(&mesh_file, "-m", "--mesh",
@@ -524,8 +524,8 @@ JacobianPreconditioner::~JacobianPreconditioner()
 RubberOperator::RubberOperator(Array<ParFiniteElementSpace *> &fes,
                               Array<Array<int> *> &ess_bdr,
                               Array<int> &trueOffsets,
-                               real_t rel_tol,
-                               real_t abs_tol,
+                               double rel_tol,
+                               double abs_tol,
                               int iter,
                               Coefficient &c_mu)
   : Operator(fes[0]->TrueVSize() + fes[1]->TrueVSize()),
@@ -69,11 +69,11 @@ using namespace mfem;

 // Constants used in the Hamiltonian
 static int prob_ = 0;
-static real_t m_ = 1.0;
-static real_t k_ = 1.0;
+static double m_ = 1.0;
+static double k_ = 1.0;

 // Hamiltonian functional, see below for implementation
-real_t hamiltonian(real_t q, real_t p, real_t t);
+double hamiltonian(double q, double p, double t);

 class GradT : public Operator
 {
@@ -94,7 +94,7 @@ int main(int argc, char *argv[])
   // 1. Parse command-line options.
   int order  = 1;
   int nsteps = 100;
-   real_t dt  = 0.1;
+   double dt  = 0.1;
   bool visualization = true;
   bool gnuplot = false;

@@ -136,7 +136,7 @@ int main(int argc, char *argv[])
   siaSolver.Init(P,F);

   // 3. Set the initial conditions
-   real_t t = 0.0;
+   double t = 0.0;
   Vector q(1), p(1);
   Vector e(nsteps+1);
   q(0) = 0.0;
@@ -160,7 +160,7 @@ int main(int argc, char *argv[])
   Vector x1(3); x1 = 0.0;

   // 6. Perform time-stepping
-   real_t e_mean = 0.0;
+   double e_mean = 0.0;

   for (int i = 0; i < nsteps; i++)
   {
@@ -210,13 +210,13 @@ int main(int argc, char *argv[])

   // 7. Compute and display mean and standard deviation of the energy
   e_mean /= (nsteps + 1);
-   real_t e_var = 0.0;
+   double e_var = 0.0;
   for (int i=0; i<=nsteps; i++)
   {
      e_var += pow(e[i] - e_mean, 2);
   }
   e_var /= (nsteps + 1);
-   real_t e_sd = sqrt(e_var);
+   double e_sd = sqrt(e_var);
   cout << endl << "Mean and standard deviation of the energy" << endl;
   cout << e_mean << "\t" << e_sd << endl;

@@ -256,9 +256,9 @@ int main(int argc, char *argv[])
   }
 }

-real_t hamiltonian(real_t q, real_t p, real_t t)
+double hamiltonian(double q, double p, double t)
 {
-   real_t h = 1.0 - 0.5 / m_ + 0.5 * p * p / m_;
+   double h = 1.0 - 0.5 / m_ + 0.5 * p * p / m_;
   switch (prob_)
   {
      case 1:
@@ -74,11 +74,11 @@ using namespace mfem;

 // Constants used in the Hamiltonian
 static int prob_ = 0;
-static real_t m_ = 1.0;
-static real_t k_ = 1.0;
+static double m_ = 1.0;
+static double k_ = 1.0;

 // Hamiltonian functional, see below for implementation
-real_t hamiltonian(real_t q, real_t p, real_t t);
+double hamiltonian(double q, double p, double t);

 class GradT : public Operator
 {
@@ -106,7 +106,7 @@ int main(int argc, char *argv[])
   // 2. Parse command-line options.
   int order  = 1;
   int nsteps = 100;
-   real_t dt  = 0.1;
+   double dt  = 0.1;
   bool visualization = true;
   bool gnuplot = false;

@@ -154,11 +154,11 @@ int main(int argc, char *argv[])
   siaSolver.Init(P,F);

   // 4. Set the initial conditions
-   real_t t = 0.0;
+   double t = 0.0;
   Vector q(1), p(1);
   Vector e(nsteps+1);
-   q(0) = sin(2.0*M_PI*(real_t)myid/num_procs);
-   p(0) = cos(2.0*M_PI*(real_t)myid/num_procs);
+   q(0) = sin(2.0*M_PI*(double)myid/num_procs);
+   p(0) = cos(2.0*M_PI*(double)myid/num_procs);

   // 5. Prepare GnuPlot output file if needed
   ostringstream oss;
@@ -181,7 +181,7 @@ int main(int argc, char *argv[])
   Vector x1(3); x1 = 0.0;

   // 7. Perform time-stepping
-   real_t e_mean = 0.0;
+   double e_mean = 0.0;

   for (int i = 0; i < nsteps; i++)
   {
@@ -238,21 +238,20 @@ int main(int argc, char *argv[])

   // 8. Compute and display mean and standard deviation of the energy
   e_mean /= (nsteps + 1);
-   real_t e_var = 0.0;
+   double e_var = 0.0;
   for (int i = 0; i <= nsteps; i++)
   {
      e_var += pow(e[i] - e_mean, 2);
   }
   e_var /= (nsteps + 1);
-   real_t e_sd = sqrt(e_var);
+   double e_sd = sqrt(e_var);

-   real_t e_loc_stats[2];
-   real_t *e_stats = (myid == 0) ? new real_t[2 * num_procs] : (real_t*)NULL;
+   double e_loc_stats[2];
+   double *e_stats = (myid == 0) ? new double[2 * num_procs] : (double*)NULL;

   e_loc_stats[0] = e_mean;
   e_loc_stats[1] = e_sd;
-   MPI_Gather(e_loc_stats, 2, MPITypeMap<real_t>::mpi_type, e_stats, 2,
-              MPITypeMap<real_t>::mpi_type, 0, comm);
+   MPI_Gather(e_loc_stats, 2, MPI_DOUBLE, e_stats, 2, MPI_DOUBLE, 0, comm);

   if (myid == 0)
   {
@@ -325,9 +324,9 @@ int main(int argc, char *argv[])
   }
 }

-real_t hamiltonian(real_t q, real_t p, real_t t)
+double hamiltonian(double q, double p, double t)
 {
-   real_t h = 1.0 - 0.5 / m_ + 0.5 * p * p / m_;
+   double h = 1.0 - 0.5 / m_ + 0.5 * p * p / m_;
   switch (prob_)
   {
      case 1:
@@ -57,13 +57,13 @@
 using namespace std;
 using namespace mfem;

-static real_t mu_ = 1.0;
-static real_t epsilon_ = 1.0;
-static real_t sigma_ = 20.0;
-static real_t omega_ = 10.0;
+static double mu_ = 1.0;
+static double epsilon_ = 1.0;
+static double sigma_ = 20.0;
+static double omega_ = 10.0;

-real_t u0_real_exact(const Vector &);
-real_t u0_imag_exact(const Vector &);
+double u0_real_exact(const Vector &);
+double u0_imag_exact(const Vector &);

 void u1_real_exact(const Vector &, Vector &);
 void u1_imag_exact(const Vector &, Vector &);
@@ -80,8 +80,8 @@ int main(int argc, char *argv[])
   int ref_levels = 0;
   int order = 1;
   int prob = 0;
-   real_t freq = -1.0;
-   real_t a_coef = 0.0;
+   double freq = -1.0;
+   double a_coef = 0.0;
   bool visualization = 1;
   bool herm_conv = true;
   bool exact_sol = true;
@@ -412,7 +412,7 @@ int main(int argc, char *argv[])
               break; // This should be unreachable
         }
      }
-      real_t s = (prob != 1) ? 1.0 : -1.0;
+      double s = (prob != 1) ? 1.0 : -1.0;
      pc_i = new ScaledOperator(pc_r,
                                (conv == ComplexOperator::HERMITIAN) ?
                                s:-s);
@@ -436,8 +436,8 @@ int main(int argc, char *argv[])

   if (exact_sol)
   {
-      real_t err_r = -1.0;
-      real_t err_i = -1.0;
+      double err_r = -1.0;
+      double err_i = -1.0;

      switch (prob)
      {
@@ -524,7 +524,7 @@ int main(int argc, char *argv[])
      int i = 0;
      while (sol_sock)
      {
-         real_t t = (real_t)(i % num_frames) / num_frames;
+         double t = (double)(i % num_frames) / num_frames;
         ostringstream oss;
         oss << "Harmonic Solution (t = " << t << " T)";

@@ -555,21 +555,21 @@ bool check_for_inline_mesh(const char * mesh_file)
   return s0 == "inline-";
 }

-complex<real_t> u0_exact(const Vector &x)
+complex<double> u0_exact(const Vector &x)
 {
   int dim = x.Size();
-   complex<real_t> i(0.0, 1.0);
-   complex<real_t> alpha = (epsilon_ * omega_ - i * sigma_);
-   complex<real_t> kappa = std::sqrt(mu_ * omega_* alpha);
+   complex<double> i(0.0, 1.0);
+   complex<double> alpha = (epsilon_ * omega_ - i * sigma_);
+   complex<double> kappa = std::sqrt(mu_ * omega_* alpha);
   return std::exp(-i * kappa * x[dim - 1]);
 }

-real_t u0_real_exact(const Vector &x)
+double u0_real_exact(const Vector &x)
 {
   return u0_exact(x).real();
 }

-real_t u0_imag_exact(const Vector &x)
+double u0_imag_exact(const Vector &x)
 {
   return u0_exact(x).imag();
 }
@@ -57,13 +57,13 @@
 using namespace std;
 using namespace mfem;

-static real_t mu_ = 1.0;
-static real_t epsilon_ = 1.0;
-static real_t sigma_ = 20.0;
-static real_t omega_ = 10.0;
+static double mu_ = 1.0;
+static double epsilon_ = 1.0;
+static double sigma_ = 20.0;
+static double omega_ = 10.0;

-real_t u0_real_exact(const Vector &);
-real_t u0_imag_exact(const Vector &);
+double u0_real_exact(const Vector &);
+double u0_imag_exact(const Vector &);

 void u1_real_exact(const Vector &, Vector &);
 void u1_imag_exact(const Vector &, Vector &);
@@ -87,8 +87,8 @@ int main(int argc, char *argv[])
   int par_ref_levels = 1;
   int order = 1;
   int prob = 0;
-   real_t freq = -1.0;
-   real_t a_coef = 0.0;
+   double freq = -1.0;
+   double a_coef = 0.0;
   bool visualization = 1;
   bool herm_conv = true;
   bool exact_sol = true;
@@ -475,8 +475,8 @@ int main(int argc, char *argv[])

   if (exact_sol)
   {
-      real_t err_r = -1.0;
-      real_t err_i = -1.0;
+      double err_r = -1.0;
+      double err_i = -1.0;

      switch (prob)
      {
@@ -576,7 +576,7 @@ int main(int argc, char *argv[])
      int i = 0;
      while (sol_sock)
      {
-         real_t t = (real_t)(i % num_frames) / num_frames;
+         double t = (double)(i % num_frames) / num_frames;
         ostringstream oss;
         oss << "Harmonic Solution (t = " << t << " T)";

@@ -608,21 +608,21 @@ bool check_for_inline_mesh(const char * mesh_file)
   return s0 == "inline-";
 }

-complex<real_t> u0_exact(const Vector &x)
+complex<double> u0_exact(const Vector &x)
 {
   int dim = x.Size();
-   complex<real_t> i(0.0, 1.0);
-   complex<real_t> alpha = (epsilon_ * omega_ - i * sigma_);
-   complex<real_t> kappa = std::sqrt(mu_ * omega_* alpha);
+   complex<double> i(0.0, 1.0);
+   complex<double> alpha = (epsilon_ * omega_ - i * sigma_);
+   complex<double> kappa = std::sqrt(mu_ * omega_* alpha);
   return std::exp(-i * kappa * x[dim - 1]);
 }

-real_t u0_real_exact(const Vector &x)
+double u0_real_exact(const Vector &x)
 {
   return u0_exact(x).real();
 }

-real_t u0_imag_exact(const Vector &x)
+double u0_imag_exact(const Vector &x)
 {
   return u0_exact(x).imag();
 }
@@ -26,12 +26,13 @@
 using namespace std;
 using namespace mfem;

-/** After spatial discretization, the wave model can be written as:
+/** After spatial discretization, the conduction model can be written as:
 *
 *     d^2u/dt^2 = M^{-1}(-Ku)
 *
- *  where u is the vector representing the temperature, M is the mass,
- *  and K is the stiffness matrix.
+ *  where u is the vector representing the temperature, M is the mass matrix,
+ *  and K is the diffusion operator with diffusivity depending on u:
+ *  (\kappa + \alpha u).
 *
 *  Class WaveOperator represents the right-hand side of the above ODE.
 */
@@ -46,7 +47,7 @@ protected:

   SparseMatrix Mmat, Kmat, Kmat0;
   SparseMatrix *T; // T = M + dt K
-   real_t current_dt;
+   double current_dt;

   CGSolver M_solver; // Krylov solver for inverting the mass matrix M
   DSmoother M_prec;  // Preconditioner for the mass matrix M
@@ -58,7 +59,7 @@ protected:
   mutable Vector z; // auxiliary vector

 public:
-   WaveOperator(FiniteElementSpace &f, Array<int> &ess_bdr, real_t speed);
+   WaveOperator(FiniteElementSpace &f, Array<int> &ess_bdr,double speed);

   using SecondOrderTimeDependentOperator::Mult;
   virtual void Mult(const Vector &u, const Vector &du_dt,
@@ -68,7 +69,7 @@ public:
       d2udt2 = f(u + fac0*d2udt2,dudt + fac1*d2udt2, t),
       for the unknown d2udt2. */
   using SecondOrderTimeDependentOperator::ImplicitSolve;
-   virtual void ImplicitSolve(const real_t fac0, const real_t fac1,
+   virtual void ImplicitSolve(const double fac0, const double fac1,
                              const Vector &u, const Vector &dudt, Vector &d2udt2);

   ///
@@ -79,11 +80,12 @@ public:


 WaveOperator::WaveOperator(FiniteElementSpace &f,
-                           Array<int> &ess_bdr, real_t speed)
-   : SecondOrderTimeDependentOperator(f.GetTrueVSize(), (real_t) 0.0),
-     fespace(f), M(NULL), K(NULL), T(NULL), current_dt(0.0), z(height)
+                           Array<int> &ess_bdr, double speed)
+   : SecondOrderTimeDependentOperator(f.GetTrueVSize(), 0.0), fespace(f), M(NULL),
+     K(NULL),
+     T(NULL), current_dt(0.0), z(height)
 {
-   const real_t rel_tol = 1e-8;
+   const double rel_tol = 1e-8;

   fespace.GetEssentialTrueDofs(ess_bdr, ess_tdof_list);

@@ -131,7 +133,7 @@ void WaveOperator::Mult(const Vector &u, const Vector &du_dt,
   M_solver.Mult(z, d2udt2);
 }

-void WaveOperator::ImplicitSolve(const real_t fac0, const real_t fac1,
+void WaveOperator::ImplicitSolve(const double fac0, const double fac1,
                                 const Vector &u, const Vector &dudt, Vector &d2udt2)
 {
   // Solve the equation:
@@ -166,12 +168,12 @@ WaveOperator::~WaveOperator()
   delete c2;
 }

-real_t InitialSolution(const Vector &x)
+double InitialSolution(const Vector &x)
 {
   return exp(-x.Norml2()*x.Norml2()*30);
 }

-real_t InitialRate(const Vector &x)
+double InitialRate(const Vector &x)
 {
   return 0.0;
 }
@@ -185,9 +187,9 @@ int main(int argc, char *argv[])
   int ref_levels = 2;
   int order = 2;
   int ode_solver_type = 10;
-   real_t t_final = 0.5;
-   real_t dt = 1.0e-2;
-   real_t speed = 1.0;
+   double t_final = 0.5;
+   double dt = 1.0e-2;
+   double speed = 1.0;
   bool visualization = true;
   bool visit = true;
   bool dirichlet = true;
@@ -299,7 +301,7 @@ int main(int argc, char *argv[])
   Vector dudt;
   dudt_gf.GetTrueDofs(dudt);

-   // 7. Initialize the wave operator and the visualization.
+   // 7. Initialize the conduction operator and the visualization.
   Array<int> ess_bdr;
   if (mesh->bdr_attributes.Size())
   {
@@ -354,7 +356,7 @@ int main(int argc, char *argv[])
      else
      {
         sout.precision(precision);
-         sout << "solution\n" << *mesh << u_gf;
+         sout << "solution\n" << *mesh << dudt_gf;
         sout << "pause\n";
         sout << flush;
         cout << "GLVis visualization paused."
@@ -365,7 +367,7 @@ int main(int argc, char *argv[])
   // 8. Perform time-integration (looping over the time iterations, ti, with a
   //    time-step dt).
   ode_solver->Init(oper);
-   real_t t = 0.0;
+   double t = 0.0;

   bool last_step = false;
   for (int ti = 1; !last_step; ti++)
@@ -44,14 +44,14 @@
 using namespace std;
 using namespace mfem;

-real_t p_exact(const Vector &x);
+double p_exact(const Vector &x);
 void gradp_exact(const Vector &, Vector &);
-real_t div_gradp_exact(const Vector &x);
+double div_gradp_exact(const Vector &x);
 void v_exact(const Vector &x, Vector &v);
 void curlv_exact(const Vector &x, Vector &cv);

 int dim;
-real_t freq = 1.0, kappa;
+double freq = 1.0, kappa;

 int main(int argc, char *argv[])
 {
@@ -304,9 +304,9 @@ int main(int argc, char *argv[])
   // 12. Compute and print the L_2 norm of the error.
   if (prob == 0)
   {
-      real_t errSol = x.ComputeL2Error(gradp_coef);
-      real_t errInterp = discreteInterpolant.ComputeL2Error(gradp_coef);
-      real_t errProj = exact_proj.ComputeL2Error(gradp_coef);
+      double errSol = x.ComputeL2Error(gradp_coef);
+      double errInterp = discreteInterpolant.ComputeL2Error(gradp_coef);
+      double errProj = exact_proj.ComputeL2Error(gradp_coef);

      cout << "\n Solution of (E_h,v) = (grad p_h,v) for E_h and v in H(curl): "
           "|| E_h - grad p ||_{L_2} = " << errSol << '\n' << endl;
@@ -317,9 +317,9 @@ int main(int argc, char *argv[])
   }
   else if (prob == 1)
   {
-      real_t errSol = x.ComputeL2Error(curlv_coef);
-      real_t errInterp = discreteInterpolant.ComputeL2Error(curlv_coef);
-      real_t errProj = exact_proj.ComputeL2Error(curlv_coef);
+      double errSol = x.ComputeL2Error(curlv_coef);
+      double errInterp = discreteInterpolant.ComputeL2Error(curlv_coef);
+      double errProj = exact_proj.ComputeL2Error(curlv_coef);

      cout << "\n Solution of (E_h,w) = (curl v_h,w) for E_h and w in H(div): "
           "|| E_h - curl v ||_{L_2} = " << errSol << '\n' << endl;
@@ -337,9 +337,9 @@ int main(int argc, char *argv[])
         irs[i] = &(IntRules.Get(i, order_quad));
      }

-      real_t errSol = x.ComputeL2Error(divgradp_coef, irs);
-      real_t errInterp = discreteInterpolant.ComputeL2Error(divgradp_coef, irs);
-      real_t errProj = exact_proj.ComputeL2Error(divgradp_coef, irs);
+      double errSol = x.ComputeL2Error(divgradp_coef, irs);
+      double errInterp = discreteInterpolant.ComputeL2Error(divgradp_coef, irs);
+      double errProj = exact_proj.ComputeL2Error(divgradp_coef, irs);

      cout << "\n Solution of (f_h,q) = (div v_h,q) for f_h and q in L_2: "
           "|| f_h - div v ||_{L_2} = " << errSol << '\n' << endl;
@@ -376,7 +376,7 @@ int main(int argc, char *argv[])
   return 0;
 }

-real_t p_exact(const Vector &x)
+double p_exact(const Vector &x)
 {
   if (dim == 3)
   {
@@ -406,7 +406,7 @@ void gradp_exact(const Vector &x, Vector &f)
   }
 }

-real_t div_gradp_exact(const Vector &x)
+double div_gradp_exact(const Vector &x)
 {
   if (dim == 3)
   {
@@ -44,14 +44,14 @@
 using namespace std;
 using namespace mfem;

-real_t p_exact(const Vector &x);
+double p_exact(const Vector &x);
 void gradp_exact(const Vector &, Vector &);
-real_t div_gradp_exact(const Vector &x);
+double div_gradp_exact(const Vector &x);
 void v_exact(const Vector &x, Vector &v);
 void curlv_exact(const Vector &x, Vector &cv);

 int dim;
-real_t freq = 1.0, kappa;
+double freq = 1.0, kappa;

 int main(int argc, char *argv[])
 {
@@ -352,9 +352,9 @@ int main(int argc, char *argv[])
   // 14. Compute and print the L_2 norm of the error.
   if (prob == 0)
   {
-      real_t errSol = x.ComputeL2Error(gradp_coef);
-      real_t errInterp = discreteInterpolant.ComputeL2Error(gradp_coef);
-      real_t errProj = exact_proj.ComputeL2Error(gradp_coef);
+      double errSol = x.ComputeL2Error(gradp_coef);
+      double errInterp = discreteInterpolant.ComputeL2Error(gradp_coef);
+      double errProj = exact_proj.ComputeL2Error(gradp_coef);

      if (myid == 0)
      {
@@ -368,9 +368,9 @@ int main(int argc, char *argv[])
   }
   else if (prob == 1)
   {
-      real_t errSol = x.ComputeL2Error(curlv_coef);
-      real_t errInterp = discreteInterpolant.ComputeL2Error(curlv_coef);
-      real_t errProj = exact_proj.ComputeL2Error(curlv_coef);
+      double errSol = x.ComputeL2Error(curlv_coef);
+      double errInterp = discreteInterpolant.ComputeL2Error(curlv_coef);
+      double errProj = exact_proj.ComputeL2Error(curlv_coef);

      if (myid == 0)
      {
@@ -391,9 +391,9 @@ int main(int argc, char *argv[])
         irs[i] = &(IntRules.Get(i, order_quad));
      }

-      real_t errSol = x.ComputeL2Error(divgradp_coef, irs);
-      real_t errInterp = discreteInterpolant.ComputeL2Error(divgradp_coef, irs);
-      real_t errProj = exact_proj.ComputeL2Error(divgradp_coef, irs);
+      double errSol = x.ComputeL2Error(divgradp_coef, irs);
+      double errInterp = discreteInterpolant.ComputeL2Error(divgradp_coef, irs);
+      double errProj = exact_proj.ComputeL2Error(divgradp_coef, irs);

      if (myid == 0)
      {
@@ -441,7 +441,7 @@ int main(int argc, char *argv[])
   return 0;
 }

-real_t p_exact(const Vector &x)
+double p_exact(const Vector &x)
 {
   if (dim == 3)
   {
@@ -471,7 +471,7 @@ void gradp_exact(const Vector &x, Vector &f)
   }
 }

-real_t div_gradp_exact(const Vector &x)
+double div_gradp_exact(const Vector &x)
 {
   if (dim == 3)
   {
@@ -53,13 +53,13 @@ private:
   int dim;

   // Length of the PML Region in each direction
-   Array2D<real_t> length;
+   Array2D<double> length;

   // Computational Domain Boundary
-   Array2D<real_t> comp_dom_bdr;
+   Array2D<double> comp_dom_bdr;

   // Domain Boundary
-   Array2D<real_t> dom_bdr;
+   Array2D<double> dom_bdr;

   // Integer Array identifying elements in the PML
   // 0: in the PML, 1: not in the PML
@@ -70,13 +70,13 @@ private:

 public:
   // Constructor
-   PML(Mesh *mesh_,Array2D<real_t> length_);
+   PML(Mesh *mesh_,Array2D<double> length_);

   // Return Computational Domain Boundary
-   Array2D<real_t> GetCompDomainBdr() {return comp_dom_bdr;}
+   Array2D<double> GetCompDomainBdr() {return comp_dom_bdr;}

   // Return Domain Boundary
-   Array2D<real_t> GetDomainBdr() {return dom_bdr;}
+   Array2D<double> GetDomainBdr() {return dom_bdr;}

   // Return Markers list for elements
   Array<int> * GetMarkedPMLElements() {return &elems;}
@@ -85,7 +85,7 @@ public:
   void SetAttributes(Mesh *mesh_);

   // PML complex stretching function
-   void StretchFunction(const Vector &x, vector<complex<real_t>> &dxs);
+   void StretchFunction(const Vector &x, vector<complex<double>> &dxs);
 };

 // Class for returning the PML coefficients of the bilinear form
@@ -106,7 +106,7 @@ public:
   virtual void Eval(Vector &K, ElementTransformation &T,
                     const IntegrationPoint &ip)
   {
-      real_t x[3];
+      double x[3];
      Vector transip(x, 3);
      T.Transform(ip, transip);
      K.SetSize(vdim);
@@ -114,7 +114,7 @@ public:
   }
 };

-void maxwell_solution(const Vector &x, vector<complex<real_t>> &Eval);
+void maxwell_solution(const Vector &x, vector<complex<double>> &Eval);

 void E_bdr_data_Re(const Vector &x, Vector &E);
 void E_bdr_data_Im(const Vector &x, Vector &E);
@@ -134,12 +134,12 @@ void detJ_inv_JT_J_Re(const Vector &x, PML * pml, Vector &D);
 void detJ_inv_JT_J_Im(const Vector &x, PML * pml, Vector &D);
 void detJ_inv_JT_J_abs(const Vector &x, PML * pml, Vector &D);

-Array2D<real_t> comp_domain_bdr;
-Array2D<real_t> domain_bdr;
+Array2D<double> comp_domain_bdr;
+Array2D<double> domain_bdr;

-real_t mu = 1.0;
-real_t epsilon = 1.0;
-real_t omega;
+double mu = 1.0;
+double epsilon = 1.0;
+double omega;
 int dim;
 bool exact_known = false;

@@ -160,7 +160,7 @@ int main(int argc, char *argv[])
   int order = 1;
   int ref_levels = 3;
   int iprob = 4;
-   real_t freq = 5.0;
+   double freq = 5.0;
   bool herm_conv = true;
   bool umf_solver = false;
   bool visualization = 1;
@@ -244,7 +244,7 @@ int main(int argc, char *argv[])
   omega = 2.0 * M_PI * freq;

   // Setup PML length
-   Array2D<real_t> length(dim, 2); length = 0.0;
+   Array2D<double> length(dim, 2); length = 0.0;

   // 4. Setup the Cartesian PML region.
   switch (prob)
@@ -470,7 +470,7 @@ int main(int argc, char *argv[])

      std::unique_ptr<Operator> pc_r;
      std::unique_ptr<Operator> pc_i;
-      real_t s = (conv == ComplexOperator::HERMITIAN) ? -1.0 : 1.0;
+      double s = (conv == ComplexOperator::HERMITIAN) ? -1.0 : 1.0;
      if (pa)
      {
         // Jacobi Smoother
@@ -519,14 +519,14 @@ int main(int argc, char *argv[])
         irs[i] = &(IntRules.Get(i, order_quad));
      }

-      real_t L2Error_Re = x.real().ComputeL2Error(E_ex_Re, irs,
+      double L2Error_Re = x.real().ComputeL2Error(E_ex_Re, irs,
                                                  pml->GetMarkedPMLElements());
-      real_t L2Error_Im = x.imag().ComputeL2Error(E_ex_Im, irs,
+      double L2Error_Im = x.imag().ComputeL2Error(E_ex_Im, irs,
                                                  pml->GetMarkedPMLElements());

      ComplexGridFunction x_gf0(fespace);
      x_gf0 = 0.0;
-      real_t norm_E_Re, norm_E_Im;
+      double norm_E_Re, norm_E_Im;
      norm_E_Re = x_gf0.real().ComputeL2Error(E_ex_Re, irs,
                                              pml->GetMarkedPMLElements());
      norm_E_Im = x_gf0.imag().ComputeL2Error(E_ex_Im, irs,
@@ -593,7 +593,7 @@ int main(int argc, char *argv[])
      int i = 0;
      while (sol_sock)
      {
-         real_t t = (real_t)(i % num_frames) / num_frames;
+         double t = (double)(i % num_frames) / num_frames;
         ostringstream oss;
         oss << "Harmonic Solution (t = " << t << " T)";

@@ -617,20 +617,20 @@ int main(int argc, char *argv[])
 void source(const Vector &x, Vector &f)
 {
   Vector center(dim);
-   real_t r = 0.0;
+   double r = 0.0;
   for (int i = 0; i < dim; ++i)
   {
      center(i) = 0.5 * (comp_domain_bdr(i, 0) + comp_domain_bdr(i, 1));
      r += pow(x[i] - center[i], 2.);
   }
-   real_t n = 5.0 * omega * sqrt(epsilon * mu) / M_PI;
-   real_t coeff = pow(n, 2) / M_PI;
-   real_t alpha = -pow(n, 2) * r;
+   double n = 5.0 * omega * sqrt(epsilon * mu) / M_PI;
+   double coeff = pow(n, 2) / M_PI;
+   double alpha = -pow(n, 2) * r;
   f = 0.0;
   f[0] = coeff * exp(alpha);
 }

-void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)
+void maxwell_solution(const Vector &x, vector<complex<double>> &E)
 {
   // Initialize
   for (int i = 0; i < dim; ++i)
@@ -638,8 +638,8 @@ void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)
      E[i] = 0.0;
   }

-   complex<real_t> zi = complex<real_t>(0., 1.);
-   real_t k = omega * sqrt(epsilon * mu);
+   complex<double> zi = complex<double>(0., 1.);
+   double k = omega * sqrt(epsilon * mu);
   switch (prob)
   {
      case disc:
@@ -654,58 +654,58 @@ void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)

         if (dim == 2)
         {
-            real_t x0 = x(0) + shift(0);
-            real_t x1 = x(1) + shift(1);
-            real_t r = sqrt(x0 * x0 + x1 * x1);
-            real_t beta = k * r;
+            double x0 = x(0) + shift(0);
+            double x1 = x(1) + shift(1);
+            double r = sqrt(x0 * x0 + x1 * x1);
+            double beta = k * r;

            // Bessel functions
-            complex<real_t> Ho, Ho_r, Ho_rr;
-            Ho = jn(0, beta) + (complex<double>) zi * yn(0, beta);
-            Ho_r = -k * complex<real_t>(jn(1, beta) + (complex<double>) zi * yn(1, beta));
-            Ho_rr = -k * k * (real_t(1) / beta *
-                              complex<real_t>(jn(1, beta) + (complex<double>) zi * yn(1, beta)) -
-                              complex<real_t>(jn(2, beta) + (complex<double>) zi * yn(2, beta)));
+            complex<double> Ho, Ho_r, Ho_rr;
+            Ho = jn(0, beta) + zi * yn(0, beta);
+            Ho_r = -k * (jn(1, beta) + zi * yn(1, beta));
+            Ho_rr = -k * k * (1.0 / beta *
+                              (jn(1, beta) + zi * yn(1, beta)) -
+                              (jn(2, beta) + zi * yn(2, beta)));

            // First derivatives
-            real_t r_x = x0 / r;
-            real_t r_y = x1 / r;
-            real_t r_xy = -(r_x / r) * r_y;
-            real_t r_xx = (1.0 / r) * (1.0 - r_x * r_x);
+            double r_x = x0 / r;
+            double r_y = x1 / r;
+            double r_xy = -(r_x / r) * r_y;
+            double r_xx = (1.0 / r) * (1.0 - r_x * r_x);

-            complex<real_t> val, val_xx, val_xy;
-            val = real_t(0.25) * zi * Ho;
-            val_xx = real_t(0.25) * zi * (r_xx * Ho_r + r_x * r_x * Ho_rr);
-            val_xy = real_t(0.25) * zi * (r_xy * Ho_r + r_x * r_y * Ho_rr);
+            complex<double> val, val_xx, val_xy;
+            val = 0.25 * zi * Ho;
+            val_xx = 0.25 * zi * (r_xx * Ho_r + r_x * r_x * Ho_rr);
+            val_xy = 0.25 * zi * (r_xy * Ho_r + r_x * r_y * Ho_rr);
            E[0] = zi / k * (k * k * val + val_xx);
            E[1] = zi / k * val_xy;
         }
         else if (dim == 3)
         {
-            real_t x0 = x(0) + shift(0);
-            real_t x1 = x(1) + shift(1);
-            real_t x2 = x(2) + shift(2);
-            real_t r = sqrt(x0 * x0 + x1 * x1 + x2 * x2);
+            double x0 = x(0) + shift(0);
+            double x1 = x(1) + shift(1);
+            double x2 = x(2) + shift(2);
+            double r = sqrt(x0 * x0 + x1 * x1 + x2 * x2);

-            real_t r_x = x0 / r;
-            real_t r_y = x1 / r;
-            real_t r_z = x2 / r;
-            real_t r_xx = (1.0 / r) * (1.0 - r_x * r_x);
-            real_t r_yx = -(r_y / r) * r_x;
-            real_t r_zx = -(r_z / r) * r_x;
+            double r_x = x0 / r;
+            double r_y = x1 / r;
+            double r_z = x2 / r;
+            double r_xx = (1.0 / r) * (1.0 - r_x * r_x);
+            double r_yx = -(r_y / r) * r_x;
+            double r_zx = -(r_z / r) * r_x;

-            complex<real_t> val, val_r, val_rr;
+            complex<double> val, val_r, val_rr;
            val = exp(zi * k * r) / r;
-            val_r = val / r * (zi * k * r - real_t(1));
+            val_r = val / r * (zi * k * r - 1.0);
            val_rr = val / (r * r) * (-k * k * r * r
-                                      - real_t(2) * zi * k * r + real_t(2));
+                                      - 2.0 * zi * k * r + 2.0);

-            complex<real_t> val_xx, val_yx, val_zx;
+            complex<double> val_xx, val_yx, val_zx;
            val_xx = val_rr * r_x * r_x + val_r * r_xx;
            val_yx = val_rr * r_x * r_y + val_r * r_yx;
            val_zx = val_rr * r_x * r_z + val_r * r_zx;

-            complex<real_t> alpha = zi * k / real_t(4) / (real_t) M_PI / k / k;
+            complex<double> alpha = zi * k / 4.0 / M_PI / k / k;
            E[0] = alpha * (k * k * val + val_xx);
            E[1] = alpha * val_yx;
            E[2] = alpha * val_zx;
@@ -717,12 +717,12 @@ void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)
         // T_10 mode
         if (dim == 3)
         {
-            real_t k10 = sqrt(k * k - M_PI * M_PI);
-            E[1] = -zi * k / (real_t) M_PI * sin((real_t) M_PI*x(2))*exp(zi * k10 * x(0));
+            double k10 = sqrt(k * k - M_PI * M_PI);
+            E[1] = -zi * k / M_PI * sin(M_PI*x(2))*exp(zi * k10 * x(0));
         }
         else if (dim == 2)
         {
-            E[1] = -zi * k / (real_t) M_PI * exp(zi * k * x(0));
+            E[1] = -zi * k / M_PI * exp(zi * k * x(0));
         }
         break;
      }
@@ -733,7 +733,7 @@ void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)

 void E_exact_Re(const Vector &x, Vector &E)
 {
-   vector<complex<real_t>> Eval(E.Size());
+   vector<complex<double>> Eval(E.Size());
   maxwell_solution(x, Eval);
   for (int i = 0; i < dim; ++i)
   {
@@ -743,7 +743,7 @@ void E_exact_Re(const Vector &x, Vector &E)

 void E_exact_Im(const Vector &x, Vector &E)
 {
-   vector<complex<real_t>> Eval(E.Size());
+   vector<complex<double>> Eval(E.Size());
   maxwell_solution(x, Eval);
   for (int i = 0; i < dim; ++i)
   {
@@ -768,7 +768,7 @@ void E_bdr_data_Re(const Vector &x, Vector &E)
   }
   if (!in_pml)
   {
-      vector<complex<real_t>> Eval(E.Size());
+      vector<complex<double>> Eval(E.Size());
      maxwell_solution(x, Eval);
      for (int i = 0; i < dim; ++i)
      {
@@ -795,7 +795,7 @@ void E_bdr_data_Im(const Vector &x, Vector &E)
   }
   if (!in_pml)
   {
-      vector<complex<real_t>> Eval(E.Size());
+      vector<complex<double>> Eval(E.Size());
      maxwell_solution(x, Eval);
      for (int i = 0; i < dim; ++i)
      {
@@ -806,8 +806,8 @@ void E_bdr_data_Im(const Vector &x, Vector &E)

 void detJ_JT_J_inv_Re(const Vector &x, PML * pml, Vector &D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det(1.0, 0.0);
+   vector<complex<double>> dxs(dim);
+   complex<double> det(1.0, 0.0);
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -817,14 +817,14 @@ void detJ_JT_J_inv_Re(const Vector &x, PML * pml, Vector &D)

   for (int i = 0; i < dim; ++i)
   {
-      D(i) = (det / pow(dxs[i], real_t(2))).real();
+      D(i) = (det / pow(dxs[i], 2)).real();
   }
 }

 void detJ_JT_J_inv_Im(const Vector &x, PML * pml, Vector &D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det = 1.0;
+   vector<complex<double>> dxs(dim);
+   complex<double> det = 1.0;
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -834,14 +834,14 @@ void detJ_JT_J_inv_Im(const Vector &x, PML * pml, Vector &D)

   for (int i = 0; i < dim; ++i)
   {
-      D(i) = (det / pow(dxs[i], real_t(2))).imag();
+      D(i) = (det / pow(dxs[i], 2)).imag();
   }
 }

 void detJ_JT_J_inv_abs(const Vector &x, PML * pml, Vector &D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det = 1.0;
+   vector<complex<double>> dxs(dim);
+   complex<double> det = 1.0;
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -851,14 +851,14 @@ void detJ_JT_J_inv_abs(const Vector &x, PML * pml, Vector &D)

   for (int i = 0; i < dim; ++i)
   {
-      D(i) = abs(det / pow(dxs[i], real_t(2)));
+      D(i) = abs(det / pow(dxs[i], 2));
   }
 }

 void detJ_inv_JT_J_Re(const Vector &x, PML * pml, Vector &D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det(1.0, 0.0);
+   vector<complex<double>> dxs(dim);
+   complex<double> det(1.0, 0.0);
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -869,21 +869,21 @@ void detJ_inv_JT_J_Re(const Vector &x, PML * pml, Vector &D)
   // in the 2D case the coefficient is scalar 1/det(J)
   if (dim == 2)
   {
-      D = (real_t(1) / det).real();
+      D = (1.0 / det).real();
   }
   else
   {
      for (int i = 0; i < dim; ++i)
      {
-         D(i) = (pow(dxs[i], real_t(2)) / det).real();
+         D(i) = (pow(dxs[i], 2) / det).real();
      }
   }
 }

 void detJ_inv_JT_J_Im(const Vector &x, PML * pml, Vector &D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det = 1.0;
+   vector<complex<double>> dxs(dim);
+   complex<double> det = 1.0;
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -893,21 +893,21 @@ void detJ_inv_JT_J_Im(const Vector &x, PML * pml, Vector &D)

   if (dim == 2)
   {
-      D = (real_t(1) / det).imag();
+      D = (1.0 / det).imag();
   }
   else
   {
      for (int i = 0; i < dim; ++i)
      {
-         D(i) = (pow(dxs[i], real_t(2)) / det).imag();
+         D(i) = (pow(dxs[i], 2) / det).imag();
      }
   }
 }

 void detJ_inv_JT_J_abs(const Vector &x, PML * pml, Vector &D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det = 1.0;
+   vector<complex<double>> dxs(dim);
+   complex<double> det = 1.0;
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -917,18 +917,18 @@ void detJ_inv_JT_J_abs(const Vector &x, PML * pml, Vector &D)

   if (dim == 2)
   {
-      D = abs(real_t(1) / det);
+      D = abs(1.0 / det);
   }
   else
   {
      for (int i = 0; i < dim; ++i)
      {
-         D(i) = abs(pow(dxs[i], real_t(2)) / det);
+         D(i) = abs(pow(dxs[i], 2) / det);
      }
   }
 }

-PML::PML(Mesh *mesh_, Array2D<real_t> length_)
+PML::PML(Mesh *mesh_, Array2D<double> length_)
   : mesh(mesh_), length(length_)
 {
   dim = mesh->Dimension();
@@ -979,7 +979,7 @@ void PML::SetAttributes(Mesh *mesh_)
      for (int iv = 0; iv < nrvert; ++iv)
      {
         int vert_idx = vertices[iv];
-         real_t *coords = mesh_->GetVertex(vert_idx);
+         double *coords = mesh_->GetVertex(vert_idx);
         for (int comp = 0; comp < dim; ++comp)
         {
            if (coords[comp] > comp_dom_bdr(comp, 1) ||
@@ -1000,14 +1000,14 @@ void PML::SetAttributes(Mesh *mesh_)
 }

 void PML::StretchFunction(const Vector &x,
-                          vector<complex<real_t>> &dxs)
+                          vector<complex<double>> &dxs)
 {
-   complex<real_t> zi = complex<real_t>(0., 1.);
+   complex<double> zi = complex<double>(0., 1.);

-   real_t n = 2.0;
-   real_t c = 5.0;
-   real_t coeff;
-   real_t k = omega * sqrt(epsilon * mu);
+   double n = 2.0;
+   double c = 5.0;
+   double coeff;
+   double k = omega * sqrt(epsilon * mu);

   // Stretch in each direction independently
   for (int i = 0; i < dim; ++i)
@@ -1016,14 +1016,14 @@ void PML::StretchFunction(const Vector &x,
      if (x(i) >= comp_domain_bdr(i, 1))
      {
         coeff = n * c / k / pow(length(i, 1), n);
-         dxs[i] = real_t(1) + zi * coeff *
-                  abs(pow(x(i) - comp_domain_bdr(i, 1), n - real_t(1)));
+         dxs[i] = 1.0 + zi * coeff *
+                  abs(pow(x(i) - comp_domain_bdr(i, 1), n - 1.0));
      }
      if (x(i) <= comp_domain_bdr(i, 0))
      {
         coeff = n * c / k / pow(length(i, 0), n);
-         dxs[i] = real_t(1) + zi * coeff *
-                  abs(pow(x(i) - comp_domain_bdr(i, 0), n - real_t(1)));
+         dxs[i] = 1.0 + zi * coeff *
+                  abs(pow(x(i) - comp_domain_bdr(i, 0), n - 1.0));
      }
   }
 }
@@ -52,13 +52,13 @@ private:
   int dim;

   // Length of the PML Region in each direction
-   Array2D<real_t> length;
+   Array2D<double> length;

   // Computational Domain Boundary
-   Array2D<real_t> comp_dom_bdr;
+   Array2D<double> comp_dom_bdr;

   // Domain Boundary
-   Array2D<real_t> dom_bdr;
+   Array2D<double> dom_bdr;

   // Integer Array identifying elements in the PML
   // 0: in the PML, 1: not in the PML
@@ -69,13 +69,13 @@ private:

 public:
   // Constructor
-   PML(Mesh *mesh_,Array2D<real_t> length_);
+   PML(Mesh *mesh_,Array2D<double> length_);

   // Return Computational Domain Boundary
-   Array2D<real_t> GetCompDomainBdr() {return comp_dom_bdr;}
+   Array2D<double> GetCompDomainBdr() {return comp_dom_bdr;}

   // Return Domain Boundary
-   Array2D<real_t> GetDomainBdr() {return dom_bdr;}
+   Array2D<double> GetDomainBdr() {return dom_bdr;}

   // Return Markers list for elements
   Array<int> * GetMarkedPMLElements() {return &elems;}
@@ -84,7 +84,7 @@ public:
   void SetAttributes(ParMesh *pmesh);

   // PML complex stretching function
-   void StretchFunction(const Vector &x, vector<complex<real_t>> &dxs);
+   void StretchFunction(const Vector &x, vector<complex<double>> &dxs);
 };

 // Class for returning the PML coefficients of the bilinear form
@@ -105,7 +105,7 @@ public:
   virtual void Eval(Vector &K, ElementTransformation &T,
                     const IntegrationPoint &ip)
   {
-      real_t x[3];
+      double x[3];
      Vector transip(x, 3);
      T.Transform(ip, transip);
      K.SetSize(vdim);
@@ -113,7 +113,7 @@ public:
   }
 };

-void maxwell_solution(const Vector &x, vector<complex<real_t>> &Eval);
+void maxwell_solution(const Vector &x, vector<complex<double>> &Eval);

 void E_bdr_data_Re(const Vector &x, Vector &E);
 void E_bdr_data_Im(const Vector &x, Vector &E);
@@ -133,12 +133,12 @@ void detJ_inv_JT_J_Re(const Vector &x, PML * pml, Vector & D);
 void detJ_inv_JT_J_Im(const Vector &x, PML * pml, Vector & D);
 void detJ_inv_JT_J_abs(const Vector &x, PML * pml, Vector & D);

-Array2D<real_t> comp_domain_bdr;
-Array2D<real_t> domain_bdr;
+Array2D<double> comp_domain_bdr;
+Array2D<double> domain_bdr;

-real_t mu = 1.0;
-real_t epsilon = 1.0;
-real_t omega;
+double mu = 1.0;
+double epsilon = 1.0;
+double omega;
 int dim;
 bool exact_known = false;

@@ -166,11 +166,10 @@ int main(int argc, char *argv[])
   int ref_levels = 1;
   int par_ref_levels = 2;
   int iprob = 4;
-   real_t freq = 5.0;
+   double freq = 5.0;
   bool herm_conv = true;
   bool slu_solver  = false;
   bool mumps_solver = false;
-   bool strumpack_solver = false;
   bool visualization = 1;
   bool pa = false;
   const char *device_config = "cpu";
@@ -201,11 +200,6 @@ int main(int argc, char *argv[])
 #ifdef MFEM_USE_MUMPS
   args.AddOption(&mumps_solver, "-mumps", "--mumps-solver", "-no-mumps",
                  "--no-mumps-solver", "Use the MUMPS Solver.");
-#endif
-#ifdef MFEM_USE_STRUMPACK
-   args.AddOption(&strumpack_solver, "-strumpack", "--strumpack-solver",
-                  "-no-strumpack", "--no-strumpack-solver",
-                  "Use the STRUMPACK Solver.");
 #endif
   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
                  "--no-visualization",
@@ -215,14 +209,13 @@ int main(int argc, char *argv[])
   args.AddOption(&device_config, "-d", "--device",
                  "Device configuration string, see Device::Configure().");
   args.Parse();
-   if (slu_solver + mumps_solver + strumpack_solver > 1)
+   if (slu_solver && mumps_solver)
   {
      if (myid == 0)
-         cout << "WARNING: More than one of SuperLU, MUMPS, and STRUMPACK have"
-              << " been selected, please choose only one." << endl
+         cout << "WARNING: Both SuperLU and MUMPS have been selected,"
+              << " please choose either one." << endl
              << "         Defaulting to SuperLU." << endl;
      mumps_solver = false;
-      strumpack_solver = false;
   }

   if (iprob > 4) { iprob = 4; }
@@ -278,7 +271,7 @@ int main(int argc, char *argv[])
   omega = 2.0 * M_PI * freq;

   // Setup PML length
-   Array2D<real_t> length(dim, 2); length = 0.0;
+   Array2D<double> length(dim, 2); length = 0.0;

   // 5. Setup the Cartesian PML region.
   switch (prob)
@@ -481,24 +474,6 @@ int main(int argc, char *argv[])
      delete A;
   }
 #endif
-#ifdef MFEM_USE_STRUMPACK
-   if (!pa && strumpack_solver)
-   {
-      HypreParMatrix *A = Ah.As<ComplexHypreParMatrix>()->GetSystemMatrix();
-      STRUMPACKRowLocMatrix SA(*A);
-      STRUMPACKSolver strumpack(MPI_COMM_WORLD, argc, argv);
-      strumpack.SetPrintFactorStatistics(false);
-      strumpack.SetPrintSolveStatistics(false);
-      strumpack.SetKrylovSolver(strumpack::KrylovSolver::DIRECT);
-      strumpack.SetReorderingStrategy(strumpack::ReorderingStrategy::METIS);
-      strumpack.SetMatching(strumpack::MatchingJob::NONE);
-      strumpack.SetCompression(strumpack::CompressionType::NONE);
-      strumpack.SetFromCommandLine();
-      strumpack.SetOperator(SA);
-      strumpack.Mult(B, X);
-      delete A;
-   }
-#endif
 #ifdef MFEM_USE_MUMPS
   if (!pa && mumps_solver)
   {
@@ -518,7 +493,7 @@ int main(int argc, char *argv[])
   //
   //    In PML:   1/mu (abs(1/det(J) J^T J) Curl E, Curl F)
   //              + omega^2 * epsilon (abs(det(J) * (J^T J)^-1) * E, F)
-   if (pa || (!slu_solver && !mumps_solver && !strumpack_solver))
+   if (pa || (!slu_solver && !mumps_solver))
   {
      ConstantCoefficient absomeg(pow(omega, 2) * epsilon);
      RestrictedCoefficient restr_absomeg(absomeg,attr);
@@ -599,14 +574,14 @@ int main(int argc, char *argv[])
         irs[i] = &(IntRules.Get(i, order_quad));
      }

-      real_t L2Error_Re = x.real().ComputeL2Error(E_ex_Re, irs,
+      double L2Error_Re = x.real().ComputeL2Error(E_ex_Re, irs,
                                                  pml->GetMarkedPMLElements());
-      real_t L2Error_Im = x.imag().ComputeL2Error(E_ex_Im, irs,
+      double L2Error_Im = x.imag().ComputeL2Error(E_ex_Im, irs,
                                                  pml->GetMarkedPMLElements());

      ParComplexGridFunction x_gf0(fespace);
      x_gf0 = 0.0;
-      real_t norm_E_Re, norm_E_Im;
+      double norm_E_Re, norm_E_Im;
      norm_E_Re = x_gf0.real().ComputeL2Error(E_ex_Re, irs,
                                              pml->GetMarkedPMLElements());
      norm_E_Im = x_gf0.imag().ComputeL2Error(E_ex_Im, irs,
@@ -694,7 +669,7 @@ int main(int argc, char *argv[])
         int i = 0;
         while (sol_sock)
         {
-            real_t t = (real_t)(i % num_frames) / num_frames;
+            double t = (double)(i % num_frames) / num_frames;
            ostringstream oss;
            oss << "Harmonic Solution (t = " << t << " T)";

@@ -718,20 +693,20 @@ int main(int argc, char *argv[])
 void source(const Vector &x, Vector &f)
 {
   Vector center(dim);
-   real_t r = 0.0;
+   double r = 0.0;
   for (int i = 0; i < dim; ++i)
   {
      center(i) = 0.5 * (comp_domain_bdr(i, 0) + comp_domain_bdr(i, 1));
      r += pow(x[i] - center[i], 2.);
   }
-   real_t n = 5.0 * omega * sqrt(epsilon * mu) / M_PI;
-   real_t coeff = pow(n, 2) / M_PI;
-   real_t alpha = -pow(n, 2) * r;
+   double n = 5.0 * omega * sqrt(epsilon * mu) / M_PI;
+   double coeff = pow(n, 2) / M_PI;
+   double alpha = -pow(n, 2) * r;
   f = 0.0;
   f[0] = coeff * exp(alpha);
 }

-void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)
+void maxwell_solution(const Vector &x, vector<complex<double>> &E)
 {
   // Initialize
   for (int i = 0; i < dim; ++i)
@@ -739,8 +714,8 @@ void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)
      E[i] = 0.0;
   }

-   complex<real_t> zi = complex<real_t>(0., 1.);
-   real_t k = omega * sqrt(epsilon * mu);
+   complex<double> zi = complex<double>(0., 1.);
+   double k = omega * sqrt(epsilon * mu);
   switch (prob)
   {
      case disc:
@@ -755,58 +730,58 @@ void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)

         if (dim == 2)
         {
-            real_t x0 = x(0) + shift(0);
-            real_t x1 = x(1) + shift(1);
-            real_t r = sqrt(x0 * x0 + x1 * x1);
-            real_t beta = k * r;
+            double x0 = x(0) + shift(0);
+            double x1 = x(1) + shift(1);
+            double r = sqrt(x0 * x0 + x1 * x1);
+            double beta = k * r;

            // Bessel functions
-            complex<real_t> Ho, Ho_r, Ho_rr;
-            Ho = jn(0, beta) + (complex<double>) zi * yn(0, beta);
-            Ho_r = -k * complex<real_t>(jn(1, beta) + (complex<double>) zi * yn(1, beta));
-            Ho_rr = -k * k * complex<real_t>(1.0 / beta *
-                                             (jn(1, beta) + (complex<double>) zi * yn(1, beta)) -
-                                             (jn(2, beta) + (complex<double>) zi * yn(2, beta)));
+            complex<double> Ho, Ho_r, Ho_rr;
+            Ho = jn(0, beta) + zi * yn(0, beta);
+            Ho_r = -k * (jn(1, beta) + zi * yn(1, beta));
+            Ho_rr = -k * k * (1.0 / beta *
+                              (jn(1, beta) + zi * yn(1, beta)) -
+                              (jn(2, beta) + zi * yn(2, beta)));

            // First derivatives
-            real_t r_x = x0 / r;
-            real_t r_y = x1 / r;
-            real_t r_xy = -(r_x / r) * r_y;
-            real_t r_xx = (1.0 / r) * (1.0 - r_x * r_x);
+            double r_x = x0 / r;
+            double r_y = x1 / r;
+            double r_xy = -(r_x / r) * r_y;
+            double r_xx = (1.0 / r) * (1.0 - r_x * r_x);

-            complex<real_t> val, val_xx, val_xy;
-            val = real_t(0.25) * zi * Ho;
-            val_xx = real_t(0.25) * zi * (r_xx * Ho_r + r_x * r_x * Ho_rr);
-            val_xy = real_t(0.25) * zi * (r_xy * Ho_r + r_x * r_y * Ho_rr);
+            complex<double> val, val_xx, val_xy;
+            val = 0.25 * zi * Ho;
+            val_xx = 0.25 * zi * (r_xx * Ho_r + r_x * r_x * Ho_rr);
+            val_xy = 0.25 * zi * (r_xy * Ho_r + r_x * r_y * Ho_rr);
            E[0] = zi / k * (k * k * val + val_xx);
            E[1] = zi / k * val_xy;
         }
         else if (dim == 3)
         {
-            real_t x0 = x(0) + shift(0);
-            real_t x1 = x(1) + shift(1);
-            real_t x2 = x(2) + shift(2);
-            real_t r = sqrt(x0 * x0 + x1 * x1 + x2 * x2);
+            double x0 = x(0) + shift(0);
+            double x1 = x(1) + shift(1);
+            double x2 = x(2) + shift(2);
+            double r = sqrt(x0 * x0 + x1 * x1 + x2 * x2);

-            real_t r_x = x0 / r;
-            real_t r_y = x1 / r;
-            real_t r_z = x2 / r;
-            real_t r_xx = (1.0 / r) * (1.0 - r_x * r_x);
-            real_t r_yx = -(r_y / r) * r_x;
-            real_t r_zx = -(r_z / r) * r_x;
+            double r_x = x0 / r;
+            double r_y = x1 / r;
+            double r_z = x2 / r;
+            double r_xx = (1.0 / r) * (1.0 - r_x * r_x);
+            double r_yx = -(r_y / r) * r_x;
+            double r_zx = -(r_z / r) * r_x;

-            complex<real_t> val, val_r, val_rr;
+            complex<double> val, val_r, val_rr;
            val = exp(zi * k * r) / r;
-            val_r = val / r * (zi * k * r - real_t(1));
+            val_r = val / r * (zi * k * r - 1.0);
            val_rr = val / (r * r) * (-k * k * r * r
-                                      - real_t(2) * zi * k * r + real_t(2));
+                                      - 2.0 * zi * k * r + 2.0);

-            complex<real_t> val_xx, val_yx, val_zx;
+            complex<double> val_xx, val_yx, val_zx;
            val_xx = val_rr * r_x * r_x + val_r * r_xx;
            val_yx = val_rr * r_x * r_y + val_r * r_yx;
            val_zx = val_rr * r_x * r_z + val_r * r_zx;

-            complex<real_t> alpha = zi * k / real_t(4) / (real_t) M_PI / k / k;
+            complex<double> alpha = zi * k / 4.0 / M_PI / k / k;
            E[0] = alpha * (k * k * val + val_xx);
            E[1] = alpha * val_yx;
            E[2] = alpha * val_zx;
@@ -818,12 +793,12 @@ void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)
         // T_10 mode
         if (dim == 3)
         {
-            real_t k10 = sqrt(k * k - M_PI * M_PI);
-            E[1] = -zi * k / (real_t) M_PI * sin((real_t) M_PI*x(2))*exp(zi * k10 * x(0));
+            double k10 = sqrt(k * k - M_PI * M_PI);
+            E[1] = -zi * k / M_PI * sin(M_PI*x(2))*exp(zi * k10 * x(0));
         }
         else if (dim == 2)
         {
-            E[1] = -zi * k / (real_t) M_PI * exp(zi * k * x(0));
+            E[1] = -zi * k / M_PI * exp(zi * k * x(0));
         }
         break;
      }
@@ -834,7 +809,7 @@ void maxwell_solution(const Vector &x, vector<complex<real_t>> &E)

 void E_exact_Re(const Vector &x, Vector &E)
 {
-   vector<complex<real_t>> Eval(E.Size());
+   vector<complex<double>> Eval(E.Size());
   maxwell_solution(x, Eval);
   for (int i = 0; i < dim; ++i)
   {
@@ -844,7 +819,7 @@ void E_exact_Re(const Vector &x, Vector &E)

 void E_exact_Im(const Vector &x, Vector &E)
 {
-   vector<complex<real_t>> Eval(E.Size());
+   vector<complex<double>> Eval(E.Size());
   maxwell_solution(x, Eval);
   for (int i = 0; i < dim; ++i)
   {
@@ -869,7 +844,7 @@ void E_bdr_data_Re(const Vector &x, Vector &E)
   }
   if (!in_pml)
   {
-      vector<complex<real_t>> Eval(E.Size());
+      vector<complex<double>> Eval(E.Size());
      maxwell_solution(x, Eval);
      for (int i = 0; i < dim; ++i)
      {
@@ -896,7 +871,7 @@ void E_bdr_data_Im(const Vector &x, Vector &E)
   }
   if (!in_pml)
   {
-      vector<complex<real_t>> Eval(E.Size());
+      vector<complex<double>> Eval(E.Size());
      maxwell_solution(x, Eval);
      for (int i = 0; i < dim; ++i)
      {
@@ -907,8 +882,8 @@ void E_bdr_data_Im(const Vector &x, Vector &E)

 void detJ_JT_J_inv_Re(const Vector &x, PML * pml, Vector & D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det(1.0, 0.0);
+   vector<complex<double>> dxs(dim);
+   complex<double> det(1.0, 0.0);
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -918,14 +893,14 @@ void detJ_JT_J_inv_Re(const Vector &x, PML * pml, Vector & D)

   for (int i = 0; i < dim; ++i)
   {
-      D(i) = (det / pow(dxs[i], real_t(2))).real();
+      D(i) = (det / pow(dxs[i], 2)).real();
   }
 }

 void detJ_JT_J_inv_Im(const Vector &x, PML * pml, Vector & D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det = 1.0;
+   vector<complex<double>> dxs(dim);
+   complex<double> det = 1.0;
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -935,14 +910,14 @@ void detJ_JT_J_inv_Im(const Vector &x, PML * pml, Vector & D)

   for (int i = 0; i < dim; ++i)
   {
-      D(i) = (det / pow(dxs[i], real_t(2))).imag();
+      D(i) = (det / pow(dxs[i], 2)).imag();
   }
 }

 void detJ_JT_J_inv_abs(const Vector &x, PML * pml, Vector & D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det = 1.0;
+   vector<complex<double>> dxs(dim);
+   complex<double> det = 1.0;
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -952,14 +927,14 @@ void detJ_JT_J_inv_abs(const Vector &x, PML * pml, Vector & D)

   for (int i = 0; i < dim; ++i)
   {
-      D(i) = abs(det / pow(dxs[i], real_t(2)));
+      D(i) = abs(det / pow(dxs[i], 2));
   }
 }

 void detJ_inv_JT_J_Re(const Vector &x, PML * pml, Vector & D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det(1.0, 0.0);
+   vector<complex<double>> dxs(dim);
+   complex<double> det(1.0, 0.0);
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -970,21 +945,21 @@ void detJ_inv_JT_J_Re(const Vector &x, PML * pml, Vector & D)
   // in the 2D case the coefficient is scalar 1/det(J)
   if (dim == 2)
   {
-      D = (real_t(1) / det).real();
+      D = (1.0 / det).real();
   }
   else
   {
      for (int i = 0; i < dim; ++i)
      {
-         D(i) = (pow(dxs[i], real_t(2)) / det).real();
+         D(i) = (pow(dxs[i], 2) / det).real();
      }
   }
 }

 void detJ_inv_JT_J_Im(const Vector &x, PML * pml, Vector & D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det = 1.0;
+   vector<complex<double>> dxs(dim);
+   complex<double> det = 1.0;
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -994,21 +969,21 @@ void detJ_inv_JT_J_Im(const Vector &x, PML * pml, Vector & D)

   if (dim == 2)
   {
-      D = (real_t(1) / det).imag();
+      D = (1.0 / det).imag();
   }
   else
   {
      for (int i = 0; i < dim; ++i)
      {
-         D(i) = (pow(dxs[i], real_t(2)) / det).imag();
+         D(i) = (pow(dxs[i], 2) / det).imag();
      }
   }
 }

 void detJ_inv_JT_J_abs(const Vector &x, PML * pml, Vector & D)
 {
-   vector<complex<real_t>> dxs(dim);
-   complex<real_t> det = 1.0;
+   vector<complex<double>> dxs(dim);
+   complex<double> det = 1.0;
   pml->StretchFunction(x, dxs);

   for (int i = 0; i < dim; ++i)
@@ -1018,18 +993,18 @@ void detJ_inv_JT_J_abs(const Vector &x, PML * pml, Vector & D)

   if (dim == 2)
   {
-      D = abs(real_t(1) / det);
+      D = abs(1.0 / det);
   }
   else
   {
      for (int i = 0; i < dim; ++i)
      {
-         D(i) = abs(pow(dxs[i], real_t(2)) / det);
+         D(i) = abs(pow(dxs[i], 2) / det);
      }
   }
 }

-PML::PML(Mesh *mesh_, Array2D<real_t> length_)
+PML::PML(Mesh *mesh_, Array2D<double> length_)
   : mesh(mesh_), length(length_)
 {
   dim = mesh->Dimension();
@@ -1081,7 +1056,7 @@ void PML::SetAttributes(ParMesh *pmesh)
      for (int iv = 0; iv < nrvert; ++iv)
      {
         int vert_idx = vertices[iv];
-         real_t *coords = pmesh->GetVertex(vert_idx);
+         double *coords = pmesh->GetVertex(vert_idx);
         for (int comp = 0; comp < dim; ++comp)
         {
            if (coords[comp] > comp_dom_bdr(comp, 1) ||
@@ -1102,14 +1077,14 @@ void PML::SetAttributes(ParMesh *pmesh)
 }

 void PML::StretchFunction(const Vector &x,
-                          vector<complex<real_t>> &dxs)
+                          vector<complex<double>> &dxs)
 {
-   complex<real_t> zi = complex<real_t>(0., 1.);
+   complex<double> zi = complex<double>(0., 1.);

-   real_t n = 2.0;
-   real_t c = 5.0;
-   real_t coeff;
-   real_t k = omega * sqrt(epsilon * mu);
+   double n = 2.0;
+   double c = 5.0;
+   double coeff;
+   double k = omega * sqrt(epsilon * mu);

   // Stretch in each direction independently
   for (int i = 0; i < dim; ++i)
@@ -1118,14 +1093,14 @@ void PML::StretchFunction(const Vector &x,
      if (x(i) >= comp_domain_bdr(i, 1))
      {
         coeff = n * c / k / pow(length(i, 1), n);
-         dxs[i] = real_t(1) + zi * coeff *
-                  abs(pow(x(i) - comp_domain_bdr(i, 1), n - real_t(1)));
+         dxs[i] = 1.0 + zi * coeff *
+                  abs(pow(x(i) - comp_domain_bdr(i, 1), n - 1.0));
      }
      if (x(i) <= comp_domain_bdr(i, 0))
      {
         coeff = n * c / k / pow(length(i, 0), n);
-         dxs[i] = real_t(1) + zi * coeff *
-                  abs(pow(x(i) - comp_domain_bdr(i, 0), n - real_t(1)));
+         dxs[i] = 1.0 + zi * coeff *
+                  abs(pow(x(i) - comp_domain_bdr(i, 0), n - 1.0));
      }
   }
 }
@@ -63,7 +63,7 @@
 using namespace std;
 using namespace mfem;

-static real_t a_ = 0.2;
+static double a_ = 0.2;

 // Normal to hole with boundary attribute 4
 void n4Vec(const Vector &x, Vector &n) { n = x; n[0] -= 0.5; n /= -n.Norml2(); }
@@ -73,25 +73,25 @@ Mesh * GenerateSerialMesh(int ref);
 // Compute the average value of alpha*n.Grad(sol) + beta*sol over the boundary
 // attributes marked in bdr_marker. Also computes the L2 norm of
 // alpha*n.Grad(sol) + beta*sol - gamma over the same boundary.
-real_t IntegrateBC(const GridFunction &sol, const Array<int> &bdr_marker,
-                   real_t alpha, real_t beta, real_t gamma,
-                   real_t &error);
+double IntegrateBC(const GridFunction &sol, const Array<int> &bdr_marker,
+                   double alpha, double beta, double gamma,
+                   double &error);

 int main(int argc, char *argv[])
 {
   // 1. Parse command-line options.
   int ser_ref_levels = 2;
   int order = 1;
-   real_t sigma = -1.0;
-   real_t kappa = -1.0;
+   double sigma = -1.0;
+   double kappa = -1.0;
   bool h1 = true;
   bool visualization = true;

-   real_t mat_val = 1.0;
-   real_t dbc_val = 0.0;
-   real_t nbc_val = 1.0;
-   real_t rbc_a_val = 1.0; // du/dn + a * u = b
-   real_t rbc_b_val = 1.0;
+   double mat_val = 1.0;
+   double dbc_val = 0.0;
+   double nbc_val = 1.0;
+   double rbc_a_val = 1.0; // du/dn + a * u = b
+   double rbc_b_val = 1.0;

   OptionsParser args(argc, argv);
   args.AddOption(&h1, "-h1", "--continuous", "-dg", "--discontinuous",
@@ -302,7 +302,7 @@ int main(int argc, char *argv[])
   {
      // Integrate the solution on the Dirichlet boundary and compare to the
      // expected value.
-      real_t error, avg = IntegrateBC(u, dbc_bdr, 0.0, 1.0, dbc_val, error);
+      double error, avg = IntegrateBC(u, dbc_bdr, 0.0, 1.0, dbc_val, error);

      bool hom_dbc = (dbc_val == 0.0);
      error /=  hom_dbc ? 1.0 : fabs(dbc_val);
@@ -314,7 +314,7 @@ int main(int argc, char *argv[])
   {
      // Integrate n.Grad(u) on the inhomogeneous Neumann boundary and compare
      // to the expected value.
-      real_t error, avg = IntegrateBC(u, nbc_bdr, 1.0, 0.0, nbc_val, error);
+      double error, avg = IntegrateBC(u, nbc_bdr, 1.0, 0.0, nbc_val, error);

      bool hom_nbc = (nbc_val == 0.0);
      error /=  hom_nbc ? 1.0 : fabs(nbc_val);
@@ -330,7 +330,7 @@ int main(int argc, char *argv[])
      nbc0_bdr = 0;
      nbc0_bdr[3] = 1;

-      real_t error, avg = IntegrateBC(u, nbc0_bdr, 1.0, 0.0, 0.0, error);
+      double error, avg = IntegrateBC(u, nbc0_bdr, 1.0, 0.0, 0.0, error);

      bool hom_nbc = true;
      mfem::out << "Average of n.Grad(u) on Gamma_nbc0:\t"
@@ -341,8 +341,8 @@ int main(int argc, char *argv[])
   {
      // Integrate n.Grad(u) + a * u on the Robin boundary and compare to the
      // expected value.
-      real_t error;
-      real_t avg = IntegrateBC(u, rbc_bdr, 1.0, rbc_a_val, rbc_b_val, error);
+      double error;
+      double avg = IntegrateBC(u, rbc_bdr, 1.0, rbc_a_val, rbc_b_val, error);

      bool hom_rbc = (rbc_b_val == 0.0);
      error /=  hom_rbc ? 1.0 : fabs(rbc_b_val);
@@ -383,22 +383,22 @@ int main(int argc, char *argv[])
   return 0;
 }

-void quad_trans(real_t u, real_t v, real_t &x, real_t &y, bool log = false)
+void quad_trans(double u, double v, double &x, double &y, bool log = false)
 {
-   real_t a = a_; // Radius of disc
+   double a = a_; // Radius of disc

-   real_t d = 4.0 * a * (M_SQRT2 - 2.0 * a) * (1.0 - 2.0 * v);
+   double d = 4.0 * a * (M_SQRT2 - 2.0 * a) * (1.0 - 2.0 * v);

-   real_t v0 = (1.0 + M_SQRT2) * (M_SQRT2 * a - 2.0 * v) *
+   double v0 = (1.0 + M_SQRT2) * (M_SQRT2 * a - 2.0 * v) *
               ((4.0 - 3 * M_SQRT2) * a +
                (8.0 * (M_SQRT2 - 1.0) * a - 2.0) * v) / d;

-   real_t r = 2.0 * ((M_SQRT2 - 1.0) * a * a * (1.0 - 4.0 *v) +
+   double r = 2.0 * ((M_SQRT2 - 1.0) * a * a * (1.0 - 4.0 *v) +
                     2.0 * (1.0 + M_SQRT2 *
                            (1.0 + 2.0 * (2.0 * a - M_SQRT2 - 1.0) * a)) * v * v
                    ) / d;

-   real_t t = asin(v / r) * u / v;
+   double t = asin(v / r) * u / v;
   if (log)
   {
      mfem::out << "u, v, r, v0, t "
@@ -411,7 +411,7 @@ void quad_trans(real_t u, real_t v, real_t &x, real_t &y, bool log = false)

 void trans(const Vector &u, Vector &x)
 {
-   real_t tol = 1e-4;
+   double tol = 1e-4;

   if (u[1] > 0.5 - tol || u[1] < -0.5 + tol)
   {
@@ -542,8 +542,8 @@ Mesh * GenerateSerialMesh(int ref)
      vi[0] = o +  3; vi[1] = o +  4; mesh->AddBdrSegment(vi, 3 + i);
   }

-   real_t d[2];
-   real_t a = a_ / M_SQRT2;
+   double d[2];
+   double a = a_ / M_SQRT2;

   d[0] = -1.0; d[1] = -0.5; mesh->AddVertex(d);
   d[0] = -1.0; d[1] =  0.0; mesh->AddVertex(d);
@@ -636,12 +636,12 @@ Mesh * GenerateSerialMesh(int ref)
   return mesh;
 }

-real_t IntegrateBC(const GridFunction &x, const Array<int> &bdr,
-                   real_t alpha, real_t beta, real_t gamma,
-                   real_t &error)
+double IntegrateBC(const GridFunction &x, const Array<int> &bdr,
+                   double alpha, double beta, double gamma,
+                   double &error)
 {
-   real_t nrm = 0.0;
-   real_t avg = 0.0;
+   double nrm = 0.0;
+   double avg = 0.0;
   error = 0.0;

   const bool a_is_zero = alpha == 0.0;
@@ -683,8 +683,8 @@ real_t IntegrateBC(const GridFunction &x, const Array<int> &bdr,
         IntegrationPoint eip;
         FTr->Loc1.Transform(ip, eip);
         FTr->Face->SetIntPoint(&ip);
-         real_t face_weight = FTr->Face->Weight();
-         real_t val = 0.0;
+         double face_weight = FTr->Face->Weight();
+         double val = 0.0;
         if (!a_is_zero)
         {
            FTr->Elem1->SetIntPoint(&eip);
@@ -63,7 +63,7 @@
 using namespace std;
 using namespace mfem;

-static real_t a_ = 0.2;
+static double a_ = 0.2;

 // Normal to hole with boundary attribute 4
 void n4Vec(const Vector &x, Vector &n) { n = x; n[0] -= 0.5; n /= -n.Norml2(); }
@@ -73,9 +73,9 @@ Mesh * GenerateSerialMesh(int ref);
 // Compute the average value of alpha*n.Grad(sol) + beta*sol over the boundary
 // attributes marked in bdr_marker. Also computes the L2 norm of
 // alpha*n.Grad(sol) + beta*sol - gamma over the same boundary.
-real_t IntegrateBC(const ParGridFunction &sol, const Array<int> &bdr_marker,
-                   real_t alpha, real_t beta, real_t gamma,
-                   real_t &error);
+double IntegrateBC(const ParGridFunction &sol, const Array<int> &bdr_marker,
+                   double alpha, double beta, double gamma,
+                   double &error);

 int main(int argc, char *argv[])
 {
@@ -88,16 +88,16 @@ int main(int argc, char *argv[])
   int ser_ref_levels = 2;
   int par_ref_levels = 1;
   int order = 1;
-   real_t sigma = -1.0;
-   real_t kappa = -1.0;
+   double sigma = -1.0;
+   double kappa = -1.0;
   bool h1 = true;
   bool visualization = true;

-   real_t mat_val = 1.0;
-   real_t dbc_val = 0.0;
-   real_t nbc_val = 1.0;
-   real_t rbc_a_val = 1.0; // du/dn + a * u = b
-   real_t rbc_b_val = 1.0;
+   double mat_val = 1.0;
+   double dbc_val = 0.0;
+   double nbc_val = 1.0;
+   double rbc_a_val = 1.0; // du/dn + a * u = b
+   double rbc_b_val = 1.0;

   OptionsParser args(argc, argv);
   args.AddOption(&h1, "-h1", "--continuous", "-dg", "--discontinuous",
@@ -322,7 +322,7 @@ int main(int argc, char *argv[])
   {
      // Integrate the solution on the Dirichlet boundary and compare to the
      // expected value.
-      real_t error, avg = IntegrateBC(u, dbc_bdr, 0.0, 1.0, dbc_val, error);
+      double error, avg = IntegrateBC(u, dbc_bdr, 0.0, 1.0, dbc_val, error);

      bool hom_dbc = (dbc_val == 0.0);
      error /=  hom_dbc ? 1.0 : fabs(dbc_val);
@@ -334,7 +334,7 @@ int main(int argc, char *argv[])
   {
      // Integrate n.Grad(u) on the inhomogeneous Neumann boundary and compare
      // to the expected value.
-      real_t error, avg = IntegrateBC(u, nbc_bdr, 1.0, 0.0, nbc_val, error);
+      double error, avg = IntegrateBC(u, nbc_bdr, 1.0, 0.0, nbc_val, error);

      bool hom_nbc = (nbc_val == 0.0);
      error /=  hom_nbc ? 1.0 : fabs(nbc_val);
@@ -350,7 +350,7 @@ int main(int argc, char *argv[])
      nbc0_bdr = 0;
      nbc0_bdr[3] = 1;

-      real_t error, avg = IntegrateBC(u, nbc0_bdr, 1.0, 0.0, 0.0, error);
+      double error, avg = IntegrateBC(u, nbc0_bdr, 1.0, 0.0, 0.0, error);

      bool hom_nbc = true;
      mfem::out << "Average of n.Grad(u) on Gamma_nbc0:\t"
@@ -361,7 +361,7 @@ int main(int argc, char *argv[])
   {
      // Integrate n.Grad(u) + a * u on the Robin boundary and compare to the
      // expected value.
-      real_t error, avg = IntegrateBC(u, rbc_bdr, 1.0, rbc_a_val, rbc_b_val,
+      double error, avg = IntegrateBC(u, rbc_bdr, 1.0, rbc_a_val, rbc_b_val,
                                      error);

      bool hom_rbc = (rbc_b_val == 0.0);
@@ -409,22 +409,22 @@ int main(int argc, char *argv[])
   return 0;
 }

-void quad_trans(real_t u, real_t v, real_t &x, real_t &y, bool log = false)
+void quad_trans(double u, double v, double &x, double &y, bool log = false)
 {
-   real_t a = a_; // Radius of disc
+   double a = a_; // Radius of disc

-   real_t d = 4.0 * a * (M_SQRT2 - 2.0 * a) * (1.0 - 2.0 * v);
+   double d = 4.0 * a * (M_SQRT2 - 2.0 * a) * (1.0 - 2.0 * v);

-   real_t v0 = (1.0 + M_SQRT2) * (M_SQRT2 * a - 2.0 * v) *
+   double v0 = (1.0 + M_SQRT2) * (M_SQRT2 * a - 2.0 * v) *
               ((4.0 - 3 * M_SQRT2) * a +
                (8.0 * (M_SQRT2 - 1.0) * a - 2.0) * v) / d;

-   real_t r = 2.0 * ((M_SQRT2 - 1.0) * a * a * (1.0 - 4.0 *v) +
+   double r = 2.0 * ((M_SQRT2 - 1.0) * a * a * (1.0 - 4.0 *v) +
                     2.0 * (1.0 + M_SQRT2 *
                            (1.0 + 2.0 * (2.0 * a - M_SQRT2 - 1.0) * a)) * v * v
                    ) / d;

-   real_t t = asin(v / r) * u / v;
+   double t = asin(v / r) * u / v;
   if (log)
   {
      mfem::out << "u, v, r, v0, t "
@@ -437,7 +437,7 @@ void quad_trans(real_t u, real_t v, real_t &x, real_t &y, bool log = false)

 void trans(const Vector &u, Vector &x)
 {
-   real_t tol = 1e-4;
+   double tol = 1e-4;

   if (u[1] > 0.5 - tol || u[1] < -0.5 + tol)
   {
@@ -568,8 +568,8 @@ Mesh * GenerateSerialMesh(int ref)
      vi[0] = o +  3; vi[1] = o +  4; mesh->AddBdrSegment(vi, 3 + i);
   }

-   real_t d[2];
-   real_t a = a_ / M_SQRT2;
+   double d[2];
+   double a = a_ / M_SQRT2;

   d[0] = -1.0; d[1] = -0.5; mesh->AddVertex(d);
   d[0] = -1.0; d[1] =  0.0; mesh->AddVertex(d);
@@ -662,14 +662,14 @@ Mesh * GenerateSerialMesh(int ref)
   return mesh;
 }

-real_t IntegrateBC(const ParGridFunction &x, const Array<int> &bdr,
-                   real_t alpha, real_t beta, real_t gamma,
-                   real_t &glb_err)
+double IntegrateBC(const ParGridFunction &x, const Array<int> &bdr,
+                   double alpha, double beta, double gamma,
+                   double &glb_err)
 {
-   real_t loc_vals[3];
-   real_t &nrm = loc_vals[0];
-   real_t &avg = loc_vals[1];
-   real_t &error = loc_vals[2];
+   double loc_vals[3];
+   double &nrm = loc_vals[0];
+   double &avg = loc_vals[1];
+   double &error = loc_vals[2];

   nrm = 0.0;
   avg = 0.0;
@@ -714,8 +714,8 @@ real_t IntegrateBC(const ParGridFunction &x, const Array<int> &bdr,
         IntegrationPoint eip;
         FTr->Loc1.Transform(ip, eip);
         FTr->Face->SetIntPoint(&ip);
-         real_t face_weight = FTr->Face->Weight();
-         real_t val = 0.0;
+         double face_weight = FTr->Face->Weight();
+         double val = 0.0;
         if (!a_is_zero)
         {
            FTr->Elem1->SetIntPoint(&eip);
@@ -741,12 +741,11 @@ real_t IntegrateBC(const ParGridFunction &x, const Array<int> &bdr,
      }
   }

-   real_t glb_vals[3];
-   MPI_Allreduce(loc_vals, glb_vals, 3, MPITypeMap<real_t>::mpi_type,
-                 MPI_SUM, fes.GetComm());
+   double glb_vals[3];
+   MPI_Allreduce(loc_vals, glb_vals, 3, MPI_DOUBLE, MPI_SUM, fes.GetComm());

-   real_t glb_nrm = glb_vals[0];
-   real_t glb_avg = glb_vals[1];
+   double glb_nrm = glb_vals[0];
+   double glb_avg = glb_vals[1];
   glb_err = glb_vals[2];

   // Normalize by the length of the boundary
@@ -35,7 +35,7 @@ using namespace mfem;
 // Return a mesh with a single element with vertices (0, 0), (1, 0), (1, 1),
 // (offset, 1) to demonstrate boundary conditions on a surface that is not
 // axis-aligned.
-Mesh * build_trapezoid_mesh(real_t offset)
+Mesh * build_trapezoid_mesh(double offset)
 {
   MFEM_VERIFY(offset < 0.9, "offset is too large!");

@@ -45,7 +45,7 @@ Mesh * build_trapezoid_mesh(real_t offset)
   Mesh * mesh = new Mesh(dimension, nvt, 1, nbe);

   // vertices
-   real_t vc[dimension];
+   double vc[dimension];
   vc[0] = 0.0; vc[1] = 0.0;
   mesh->AddVertex(vc);
   vc[0] = 1.0; vc[1] = 0.0;
@@ -81,7 +81,7 @@ int main(int argc, char *argv[])
   // 1. Parse command-line options.
   int order = 1;
   bool visualization = 1;
-   real_t offset = 0.3;
+   double offset = 0.3;
   bool visit = false;

   OptionsParser args(argc, argv);
@@ -38,7 +38,7 @@ using namespace mfem;
 // Return a mesh with a single element with vertices (0, 0), (1, 0), (1, 1),
 // (offset, 1) to demonstrate boundary conditions on a surface that is not
 // axis-aligned.
-Mesh * build_trapezoid_mesh(real_t offset)
+Mesh * build_trapezoid_mesh(double offset)
 {
   MFEM_VERIFY(offset < 0.9, "offset is too large!");

@@ -48,7 +48,7 @@ Mesh * build_trapezoid_mesh(real_t offset)
   Mesh * mesh = new Mesh(dimension, nvt, 1, nbe);

   // vertices
-   real_t vc[dimension];
+   double vc[dimension];
   vc[0] = 0.0; vc[1] = 0.0;
   mesh->AddVertex(vc);
   vc[0] = 1.0; vc[1] = 0.0;
@@ -97,9 +97,9 @@ int main(int argc, char *argv[])
   int order = 1;
   bool visualization = 1;
   bool reorder_space = false;
-   real_t offset = 0.3;
+   double offset = 0.3;
   bool visit = false;
-   real_t penalty = 0.0;
+   double penalty = 0.0;

   OptionsParser args(argc, argv);
   args.AddOption(&order, "-o", "--order",
@@ -34,7 +34,7 @@ void trans(const Vector &x, Vector &r);

 void sigmaFunc(const Vector &x, DenseMatrix &s);

-real_t uExact(const Vector &x)
+double uExact(const Vector &x)
 {
   return (0.25 * (2.0 + x[0]) - x[2]) * (x[2] + 0.25 * (2.0 + x[0]));
 }
@@ -167,7 +167,7 @@ int main(int argc, char *argv[])

   // 13. Compute error in the solution and its flux
   FunctionCoefficient uCoef(uExact);
-   real_t error = x.ComputeL2Error(uCoef);
+   double error = x.ComputeL2Error(uCoef);

   cout << "|u - u_h|_2 = " << error << endl;

@@ -176,7 +176,7 @@ int main(int argc, char *argv[])
   x.ComputeFlux(*integ, flux); flux *= -1.0;

   VectorFunctionCoefficient fluxCoef(3, fluxExact);
-   real_t flux_err = flux.ComputeL2Error(fluxCoef);
+   double flux_err = flux.ComputeL2Error(fluxCoef);

   cout << "|f - f_h|_2 = " << flux_err << endl;

@@ -304,8 +304,8 @@ void trans(const Vector &x, Vector &r)
 {
   r.SetSize(3);

-   real_t tol = 1e-6;
-   real_t theta = 0.0;
+   double tol = 1e-6;
+   double theta = 0.0;
   if (fabs(x[1] + 1.0) < tol)
   {
      theta = 0.25 * M_PI * (x[0] - 2.0);
@@ -337,7 +337,7 @@ void trans(const Vector &x, Vector &r)
 void sigmaFunc(const Vector &x, DenseMatrix &s)
 {
   s.SetSize(3);
-   real_t a = 17.0 - 2.0 * x[0] * (1.0 + x[0]);
+   double a = 17.0 - 2.0 * x[0] * (1.0 + x[0]);
   s(0,0) = 0.5 + x[0] * x[0] * (8.0 / a - 0.5);
   s(0,1) = x[0] * x[1] * (8.0 / a - 0.5);
   s(0,2) = 0.0;
@@ -34,7 +34,7 @@ void trans(const Vector &x, Vector &r);

 void sigmaFunc(const Vector &x, DenseMatrix &s);

-real_t uExact(const Vector &x)
+double uExact(const Vector &x)
 {
   return (0.25 * (2.0 + x[0]) - x[2]) * (x[2] + 0.25 * (2.0 + x[0]));
 }
@@ -201,7 +201,7 @@ int main(int argc, char *argv[])

   // 15. Compute error in the solution and its flux
   FunctionCoefficient uCoef(uExact);
-   real_t error = x.ComputeL2Error(uCoef);
+   double error = x.ComputeL2Error(uCoef);

   if (myid == 0) { cout << "|u - u_h|_2 = " << error << endl; }

@@ -210,7 +210,7 @@ int main(int argc, char *argv[])
   x.ComputeFlux(*integ, flux); flux *= -1.0;

   VectorFunctionCoefficient fluxCoef(3, fluxExact);
-   real_t flux_err = flux.ComputeL2Error(fluxCoef);
+   double flux_err = flux.ComputeL2Error(fluxCoef);

   if (myid == 0) { cout << "|f - f_h|_2 = " << flux_err << endl; }

@@ -349,8 +349,8 @@ void trans(const Vector &x, Vector &r)
 {
   r.SetSize(3);

-   real_t tol = 1e-6;
-   real_t theta = 0.0;
+   double tol = 1e-6;
+   double theta = 0.0;
   if (fabs(x[1] + 1.0) < tol)
   {
      theta = 0.25 * M_PI * (x[0] - 2.0);
@@ -382,7 +382,7 @@ void trans(const Vector &x, Vector &r)
 void sigmaFunc(const Vector &x, DenseMatrix &s)
 {
   s.SetSize(3);
-   real_t a = 17.0 - 2.0 * x[0] * (1.0 + x[0]);
+   double a = 17.0 - 2.0 * x[0] * (1.0 + x[0]);
   s(0,0) = 0.5 + x[0] * x[0] * (8.0 / a - 0.5);
   s(0,1) = x[0] * x[1] * (8.0 / a - 0.5);
   s(0,2) = 0.0;
@@ -100,6 +100,21 @@ int main(int argc, char *argv[])
   Device device(device_config);
   if (myid == 0) { device.Print(); }

+   if (mfem::Device::Allows(mfem::Backend::DEVICE_MASK))
+   {
+      HYPRE_SetMemoryLocation(HYPRE_MEMORY_DEVICE);
+      HYPRE_SetExecutionPolicy(HYPRE_EXEC_DEVICE);
+      HYPRE_DeviceInitialize();
+   }
+   else
+   {
+      HYPRE_SetMemoryLocation(HYPRE_MEMORY_HOST);
+      HYPRE_SetExecutionPolicy(HYPRE_EXEC_HOST);
+   }
+
+   auto loc = mfem::GetHypreMemoryLocation();
+   auto exec = mfem::GetHypreExecutionPolicy();
+
   // 4. Read the (serial) mesh from the given mesh file on all processors.  We
   //    can handle triangular, quadrilateral, tetrahedral, hexahedral, surface
   //    and volume meshes with the same code.
@@ -53,7 +53,7 @@ using namespace mfem;
 // Exact solution, E, and r.h.s., f. See below for implementation.
 void E_exact(const Vector &, Vector &);
 void f_exact(const Vector &, Vector &);
-real_t freq = 1.0, kappa;
+double freq = 1.0, kappa;
 int dim;

 int main(int argc, char *argv[])
@@ -63,7 +63,6 @@ int main(int argc, char *argv[])
   int order = 1;
   bool static_cond = false;
   bool pa = false;
-   bool nc = false;
   const char *device_config = "cpu";
   bool visualization = 1;

@@ -78,9 +77,6 @@ int main(int argc, char *argv[])
                  "--no-static-condensation", "Enable static condensation.");
   args.AddOption(&pa, "-pa", "--partial-assembly", "-no-pa",
                  "--no-partial-assembly", "Enable Partial Assembly.");
-   args.AddOption(&nc, "-nc", "--non-conforming", "-c",
-                  "--conforming",
-                  "Mark the mesh as nonconforming before partitioning.");
   args.AddOption(&device_config, "-d", "--device",
                  "Device configuration string, see Device::Configure().");
   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
@@ -106,11 +102,6 @@ int main(int argc, char *argv[])
   Mesh *mesh = new Mesh(mesh_file, 1, 1);
   dim = mesh->Dimension();
   int sdim = mesh->SpaceDimension();
-   if (nc)
-   {
-      // Can set to false to use conformal refinement for simplices.
-      mesh->EnsureNCMesh(true);
-   }

   // 4. Refine the mesh to increase the resolution. In this example we do
   //    'ref_levels' of uniform refinement. We choose 'ref_levels' to be the
@@ -42,9 +42,9 @@ using namespace std;
 using namespace mfem;

 // Piecewise-affine function which is sometimes mesh-conforming
-real_t affine_function(const Vector &p)
+double affine_function(const Vector &p)
 {
-   real_t x = p(0), y = p(1);
+   double x = p(0), y = p(1);
   if (x < 0.0)
   {
      return 1.0 + x + y;
@@ -56,7 +56,7 @@ real_t affine_function(const Vector &p)
 }

 // Piecewise-constant function which is never mesh-conforming
-real_t jump_function(const Vector &p)
+double jump_function(const Vector &p)
 {
   if (p.Normlp(2.0) > 0.4 && p.Normlp(2.0) < 0.6)
   {
@@ -70,17 +70,17 @@ real_t jump_function(const Vector &p)

 // Singular function derived from the Laplacian of the "steep wavefront" problem
 // in [2].
-real_t singular_function(const Vector &p)
+double singular_function(const Vector &p)
 {
-   real_t x = p(0), y = p(1);
-   real_t alpha = 1000.0;
-   real_t xc = 0.75, yc = 0.5;
-   real_t r0 = 0.7;
-   real_t r = sqrt(pow(x - xc,2.0) + pow(y - yc,2.0));
-   real_t num = - ( alpha - pow(alpha,3) * (pow(r,2) - pow(r0,2)) );
-   real_t denom = pow(r * ( pow(alpha,2) * pow(r0,2) + pow(alpha,2) * pow(r,2) \
+   double x = p(0), y = p(1);
+   double alpha = 1000.0;
+   double xc = 0.75, yc = 0.5;
+   double r0 = 0.7;
+   double r = sqrt(pow(x - xc,2.0) + pow(y - yc,2.0));
+   double num = - ( alpha - pow(alpha,3) * (pow(r,2) - pow(r0,2)) );
+   double denom = pow(r * ( pow(alpha,2) * pow(r0,2) + pow(alpha,2) * pow(r,2) \
                            - 2 * pow(alpha,2) * r0 * r + 1.0 ),2);
-   denom = std::max(denom, (real_t) 1.0e-8);
+   denom = max(denom,1e-8);
   return num / denom;
 }

@@ -91,9 +91,9 @@ int main(int argc, char *argv[])
   int order = 1;
   int nc_limit = 1;
   int max_elems = 100*1000;
-   real_t double_max_elems = real_t(max_elems);
+   double double_max_elems = double(max_elems);
   bool visualization = true;
-   real_t osc_threshold = 1e-3;
+   double osc_threshold = 1e-3;
   int enriched_order = 5;

   OptionsParser args(argc, argv);
@@ -42,9 +42,9 @@ using namespace std;
 using namespace mfem;

 // Piecewise-affine function which is sometimes mesh-conforming
-real_t affine_function(const Vector &p)
+double affine_function(const Vector &p)
 {
-   real_t x = p(0), y = p(1);
+   double x = p(0), y = p(1);
   if (x < 0.0)
   {
      return 1.0 + x + y;
@@ -56,7 +56,7 @@ real_t affine_function(const Vector &p)
 }

 // Piecewise-constant function which is never mesh-conforming
-real_t jump_function(const Vector &p)
+double jump_function(const Vector &p)
 {
   if (p.Normlp(2.0) > 0.4 && p.Normlp(2.0) < 0.6)
   {
@@ -70,17 +70,17 @@ real_t jump_function(const Vector &p)

 // Singular function derived from the Laplacian of the "steep wavefront" problem
 // in [2].
-real_t singular_function(const Vector &p)
+double singular_function(const Vector &p)
 {
-   real_t x = p(0), y = p(1);
-   real_t alpha = 1000.0;
-   real_t xc = 0.75, yc = 0.5;
-   real_t r0 = 0.7;
-   real_t r = sqrt(pow(x - xc,2.0) + pow(y - yc,2.0));
-   real_t num = - ( alpha - pow(alpha,3) * (pow(r,2) - pow(r0,2)) );
-   real_t denom = pow(r * ( pow(alpha,2) * pow(r0,2) + pow(alpha,2) * pow(r,2) \
+   double x = p(0), y = p(1);
+   double alpha = 1000.0;
+   double xc = 0.75, yc = 0.5;
+   double r0 = 0.7;
+   double r = sqrt(pow(x - xc,2.0) + pow(y - yc,2.0));
+   double num = - ( alpha - pow(alpha,3) * (pow(r,2) - pow(r0,2)) );
+   double denom = pow(r * ( pow(alpha,2) * pow(r0,2) + pow(alpha,2) * pow(r,2) \
                            - 2 * pow(alpha,2) * r0 * r + 1.0 ),2);
-   denom = std::max(denom, (real_t) 1.0e-8);
+   denom = max(denom,1e-8);
   return num / denom;
 }

@@ -97,10 +97,10 @@ int main(int argc, char *argv[])
   int order = 1;
   int nc_limit = 1;
   int max_elems = 1e5;
-   real_t double_max_elems = real_t(max_elems);
+   double double_max_elems = double(max_elems);
   bool visualization = true;
   bool nc_simplices = true;
-   real_t osc_threshold = 1e-3;
+   double osc_threshold = 1e-3;
   int enriched_order = 5;

   OptionsParser args(argc, argv);
@@ -199,7 +199,7 @@ int main(int argc, char *argv[])
   coeffrefiner.PreprocessMesh(pmesh);

   int globalNE = pmesh.GetGlobalNE();
-   real_t osc = coeffrefiner.GetOsc();
+   double osc = coeffrefiner.GetOsc();
   if (myid == 0)
   {
      mfem::out << "\n";
@@ -39,7 +39,7 @@ using namespace mfem;
 void E_exact(const Vector &, Vector &);
 void CurlE_exact(const Vector &, Vector &);
 void f_exact(const Vector &, Vector &);
-real_t freq = 1.0, kappa;
+double freq = 1.0, kappa;
 int dim;

 int main(int argc, char *argv[])
@@ -177,7 +177,7 @@ int main(int argc, char *argv[])

   // 13. Compute and print the H(Curl) norm of the error.
   {
-      real_t error = sol.ComputeHCurlError(&E, &CurlE);
+      double error = sol.ComputeHCurlError(&E, &CurlE);
      cout << "\n|| E_h - E ||_{H(Curl)} = " << error << '\n' << endl;
   }

@@ -376,8 +376,8 @@ void CurlE_exact(const Vector &x, Vector &dE)
 {
   if (dim == 1)
   {
-      real_t c4 = cos(kappa * x(0) + 0.4 * M_PI);
-      real_t c9 = cos(kappa * x(0) + 0.9 * M_PI);
+      double c4 = cos(kappa * x(0) + 0.4 * M_PI);
+      double c9 = cos(kappa * x(0) + 0.9 * M_PI);

      dE(0) =  0.0;
      dE(1) = -1.3 * c9;
@@ -386,9 +386,9 @@ void CurlE_exact(const Vector &x, Vector &dE)
   }
   else if (dim == 2)
   {
-      real_t c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);

      dE(0) =  1.3 * c9;
      dE(1) = -1.3 * c9;
@@ -397,13 +397,13 @@ void CurlE_exact(const Vector &x, Vector &dE)
   }
   else
   {
-      real_t s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
-      real_t sk = sin(kappa * x(2));
-      real_t ck = cos(kappa * x(2));
+      double s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double sk = sin(kappa * x(2));
+      double ck = cos(kappa * x(2));

      dE(0) =  1.2 * s4 * sk + 1.3 * M_SQRT1_2 * c9 * ck;
      dE(1) = -1.1 * s0 * sk - 1.3 * M_SQRT1_2 * c9 * ck;
@@ -416,9 +416,9 @@ void f_exact(const Vector &x, Vector &f)
 {
   if (dim == 1)
   {
-      real_t s0 = sin(kappa * x(0) + 0.0 * M_PI);
-      real_t s4 = sin(kappa * x(0) + 0.4 * M_PI);
-      real_t s9 = sin(kappa * x(0) + 0.9 * M_PI);
+      double s0 = sin(kappa * x(0) + 0.0 * M_PI);
+      double s4 = sin(kappa * x(0) + 0.4 * M_PI);
+      double s9 = sin(kappa * x(0) + 0.9 * M_PI);

      f(0) = 2.2 * s0 + 1.2 * M_SQRT1_2 * s4;
      f(1) = 1.2 * (2.0 + kappa * kappa) * s4 +
@@ -427,9 +427,9 @@ void f_exact(const Vector &x, Vector &f)
   }
   else if (dim == 2)
   {
-      real_t s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t s9 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double s9 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);

      f(0) = 0.55 * (4.0 + kappa * kappa) * s0 +
             0.6 * (M_SQRT2 - kappa * kappa) * s4;
@@ -440,14 +440,14 @@ void f_exact(const Vector &x, Vector &f)
   }
   else
   {
-      real_t s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t s9 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
-      real_t c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
-      real_t sk = sin(kappa * x(2));
-      real_t ck = cos(kappa * x(2));
+      double s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double s9 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double sk = sin(kappa * x(2));
+      double ck = cos(kappa * x(2));

      f(0) = 0.55 * (4.0 + 3.0 * kappa * kappa) * s0 * ck +
             0.6 * (M_SQRT2 - kappa * kappa) * s4 * ck -
@@ -39,7 +39,7 @@ using namespace mfem;
 void E_exact(const Vector &, Vector &);
 void CurlE_exact(const Vector &, Vector &);
 void f_exact(const Vector &, Vector &);
-real_t freq = 1.0, kappa;
+double freq = 1.0, kappa;
 int dim;

 int main(int argc, char *argv[])
@@ -224,7 +224,7 @@ int main(int argc, char *argv[])

   // 14. Compute and print the H(Curl) norm of the error.
   {
-      real_t error = sol.ComputeHCurlError(&E, &CurlE);
+      double error = sol.ComputeHCurlError(&E, &CurlE);
      if (Mpi::Root())
      {
         cout << "\n|| E_h - E ||_{H(Curl)} = " << error << '\n' << endl;
@@ -442,8 +442,8 @@ void CurlE_exact(const Vector &x, Vector &dE)
 {
   if (dim == 1)
   {
-      real_t c4 = cos(kappa * x(0) + 0.4 * M_PI);
-      real_t c9 = cos(kappa * x(0) + 0.9 * M_PI);
+      double c4 = cos(kappa * x(0) + 0.4 * M_PI);
+      double c9 = cos(kappa * x(0) + 0.9 * M_PI);

      dE(0) =  0.0;
      dE(1) = -1.3 * c9;
@@ -452,9 +452,9 @@ void CurlE_exact(const Vector &x, Vector &dE)
   }
   else if (dim == 2)
   {
-      real_t c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);

      dE(0) =  1.3 * c9;
      dE(1) = -1.3 * c9;
@@ -463,13 +463,13 @@ void CurlE_exact(const Vector &x, Vector &dE)
   }
   else
   {
-      real_t s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
-      real_t sk = sin(kappa * x(2));
-      real_t ck = cos(kappa * x(2));
+      double s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double sk = sin(kappa * x(2));
+      double ck = cos(kappa * x(2));

      dE(0) =  1.2 * s4 * sk + 1.3 * M_SQRT1_2 * c9 * ck;
      dE(1) = -1.1 * s0 * sk - 1.3 * M_SQRT1_2 * c9 * ck;
@@ -482,9 +482,9 @@ void f_exact(const Vector &x, Vector &f)
 {
   if (dim == 1)
   {
-      real_t s0 = sin(kappa * x(0) + 0.0 * M_PI);
-      real_t s4 = sin(kappa * x(0) + 0.4 * M_PI);
-      real_t s9 = sin(kappa * x(0) + 0.9 * M_PI);
+      double s0 = sin(kappa * x(0) + 0.0 * M_PI);
+      double s4 = sin(kappa * x(0) + 0.4 * M_PI);
+      double s9 = sin(kappa * x(0) + 0.9 * M_PI);

      f(0) = 2.2 * s0 + 1.2 * M_SQRT1_2 * s4;
      f(1) = 1.2 * (2.0 + kappa * kappa) * s4 +
@@ -493,9 +493,9 @@ void f_exact(const Vector &x, Vector &f)
   }
   else if (dim == 2)
   {
-      real_t s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t s9 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double s9 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);

      f(0) = 0.55 * (4.0 + kappa * kappa) * s0 +
             0.6 * (M_SQRT2 - kappa * kappa) * s4;
@@ -506,14 +506,14 @@ void f_exact(const Vector &x, Vector &f)
   }
   else
   {
-      real_t s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
-      real_t s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
-      real_t s9 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
-      real_t c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
-      real_t sk = sin(kappa * x(2));
-      real_t ck = cos(kappa * x(2));
+      double s0 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double c0 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.0 * M_PI);
+      double s4 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double c4 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.4 * M_PI);
+      double s9 = sin(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double c9 = cos(kappa * M_SQRT1_2 * (x(0) + x(1)) + 0.9 * M_PI);
+      double sk = sin(kappa * x(2));
+      double ck = cos(kappa * x(2));

      f(0) = 0.55 * (4.0 + 3.0 * kappa * kappa) * s0 * ck +
             0.6 * (M_SQRT2 - kappa * kappa) * s4 * ck -
@@ -35,8 +35,8 @@
 using namespace std;
 using namespace mfem;

-real_t GetVectorMax(int vdim, const ParGridFunction &x);
-real_t GetScalarMax(const ParGridFunction &x);
+double GetVectorMax(int vdim, const ParGridFunction &x);
+double GetScalarMax(const ParGridFunction &x);

 int main(int argc, char *argv[])
 {
@@ -140,7 +140,7 @@ int main(int argc, char *argv[])
   //    extract the corresponding parallel matrices A and M.
   HypreParMatrix *A = NULL;
   HypreParMatrix *M = NULL;
-   real_t shift = 0.0;
+   double shift = 0.0;
   {
      DenseMatrix epsilonMat(3);
      epsilonMat(0,0) = 2.0; epsilonMat(1,1) = 2.0; epsilonMat(2,2) = 2.0;
@@ -178,7 +178,7 @@ int main(int argc, char *argv[])
      m.AddDomainIntegrator(new VectorFEMassIntegrator(epsilon));
      m.Assemble();
      // shift the eigenvalue corresponding to eliminated dofs to a large value
-      m.EliminateEssentialBCDiag(ess_bdr, numeric_limits<real_t>::min());
+      m.EliminateEssentialBCDiag(ess_bdr, numeric_limits<double>::min());
      m.Finalize();

      A = a.ParallelAssemble();
@@ -204,7 +204,7 @@ int main(int argc, char *argv[])
   // 9. Compute the eigenmodes and extract the array of eigenvalues. Define
   //    parallel grid functions to represent each of the eigenmodes returned by
   //    the solver and their derivatives.
-   Array<real_t> eigenvalues;
+   Array<double> eigenvalues;
   ame->Solve();
   ame->GetEigenvalues(eigenvalues);
   ParGridFunction x(&fespace_nd);
@@ -308,10 +308,10 @@ int main(int argc, char *argv[])
               yComp.ProjectCoefficient(yCoef);
               zComp.ProjectCoefficient(zCoef);

-               real_t max_x = GetScalarMax(xComp);
-               real_t max_y = GetScalarMax(yComp);
-               real_t max_z = GetScalarMax(zComp);
-               real_t max_r = std::max(max_x, std::max(max_y, max_z));
+               double max_x = GetScalarMax(xComp);
+               double max_y = GetScalarMax(yComp);
+               double max_z = GetScalarMax(zComp);
+               double max_r = std::max(max_x, std::max(max_y, max_z));

               ostringstream x_cmd;
               x_cmd << " window_title 'Eigenmode " << i+1 << '/' << nev
@@ -368,7 +368,7 @@ int main(int argc, char *argv[])
               dyComp.ProjectCoefficient(dyCoef);
               dzComp.ProjectCoefficient(dzCoef);

-               real_t min_d = max_r / (bbMax[0] - bbMin[0]);
+               double min_d = max_r / (bbMax[0] - bbMin[0]);

               max_y = GetScalarMax(dyComp);
               max_z = GetScalarMax(dzComp);
@@ -480,9 +480,9 @@ int main(int argc, char *argv[])
               xyComp.ProjectCoefficient(xyCoef);
               zComp.ProjectCoefficient(zCoef);

-               real_t max_v = GetVectorMax(2, xyComp);
-               real_t max_s = GetScalarMax(zComp);
-               real_t max_r = std::max(max_v, max_s);
+               double max_v = GetVectorMax(2, xyComp);
+               double max_s = GetScalarMax(zComp);
+               double max_r = std::max(max_v, max_s);

               ostringstream xy_cmd;
               xy_cmd << " window_title 'Eigenmode " << i+1 << '/' << nev
@@ -523,7 +523,7 @@ int main(int argc, char *argv[])
               dxyComp.ProjectCoefficient(dxyCoef);
               dzComp.ProjectCoefficient(dzCoef);

-               real_t min_d = max_r / std::min(bbMax[0] - bbMin[0],
+               double min_d = max_r / std::min(bbMax[0] - bbMin[0],
                                               bbMax[1] - bbMin[1]);

               max_v = GetVectorMax(2, dxyComp);
@@ -649,17 +649,17 @@ int main(int argc, char *argv[])
   return 0;
 }

-real_t GetVectorMax(int vdim, const ParGridFunction &x)
+double GetVectorMax(int vdim, const ParGridFunction &x)
 {
   Vector zeroVec(vdim); zeroVec = 0.0;
   VectorConstantCoefficient zero(zeroVec);
-   real_t nrm = x.ComputeMaxError(zero);
+   double nrm = x.ComputeMaxError(zero);
   return nrm;
 }

-real_t GetScalarMax(const ParGridFunction &x)
+double GetScalarMax(const ParGridFunction &x)
 {
   ConstantCoefficient zero(0.0);
-   real_t nrm = x.ComputeMaxError(zero);
+   double nrm = x.ComputeMaxError(zero);
   return nrm;
 }
@@ -90,7 +90,7 @@ int main(int argc, char *argv[])
   const char *mesh_file = "../data/star.mesh";
   int order = 1;
   int num_refs = 3;
-   real_t alpha = 0.5;
+   double alpha = 0.5;
   bool visualization = true;
   bool verification = false;

@@ -118,17 +118,13 @@ int main(int argc, char *argv[])
   }
   args.PrintOptions(cout);

-#ifdef MFEM_USE_SINGLE
-   MFEM_ABORT("This example is not supported in single precision.");
-#endif
-
-   Array<real_t> coeffs, poles;
+   Array<double> coeffs, poles;
   int progress_steps = 1;

   // 2. Compute the rational expansion coefficients that define the
   //    integer-order PDEs.
   const int power_of_laplace = (int)floor(alpha);
-   real_t exponent_to_approximate = alpha - power_of_laplace;
+   double exponent_to_approximate = alpha - power_of_laplace;
   bool integer_order = false;
   // Check if alpha is an integer or not.
   if (abs(exponent_to_approximate) > 1e-12)
@@ -139,7 +135,7 @@ int main(int argc, char *argv[])
      ComputePartialFractionApproximation(exponent_to_approximate, coeffs,
                                          poles);

-      // If the example is built without LAPACK, the exponent_to_approximate
+      // If the example is build without LAPACK, the exponent_to_approximate
      // might be modified by the function call above.
      alpha = exponent_to_approximate + power_of_laplace;
   }
@@ -177,7 +173,7 @@ int main(int argc, char *argv[])
   // 7. Define diffusion coefficient, load, and solution GridFunction.
   auto func = [&alpha](const Vector &x)
   {
-      real_t val = 1.0;
+      double val = 1.0;
      for (int i=0; i<x.Size(); i++)
      {
         val *= sin(M_PI*x(i));
@@ -368,7 +364,7 @@ int main(int argc, char *argv[])
   {
      auto solution = [] (const Vector &x)
      {
-         real_t val = 1.0;
+         double val = 1.0;
         for (int i=0; i<x.Size(); i++)
         {
            val *= sin(M_PI*x(i));
@@ -376,7 +372,7 @@ int main(int argc, char *argv[])
         return val;
      };
      FunctionCoefficient sol(solution);
-      real_t l2_error = u.ComputeL2Error(sol);
+      double l2_error = u.ComputeL2Error(sol);

      string analytic_solution,expected_mesh;
      switch (dim)
@@ -50,8 +50,8 @@ using namespace mfem;

    See pg. A1501 of Nakatsukasa et al. [1]. */
 void RationalApproximation_AAA(const Vector &val, const Vector &pt,
-                               Array<real_t> &z, Array<real_t> &f, Vector &w,
-                               real_t tol, int max_order)
+                               Array<double> &z, Array<double> &f, Vector &w,
+                               double tol, int max_order)
 {

   // number of sample points
@@ -67,11 +67,11 @@ void RationalApproximation_AAA(const Vector &val, const Vector &pt,
   DenseMatrix C, Ctemp, A, Am;
   // auxiliary arrays and vectors
   Vector f_vec;
-   Array<real_t> c_i;
+   Array<double> c_i;

   // mean of the value vector
   Vector R(val.Size());
-   real_t mean_val = val.Sum()/size;
+   double mean_val = val.Sum()/size;

   for (int i = 0; i<R.Size(); i++) { R(i) = mean_val; }

@@ -79,10 +79,10 @@ void RationalApproximation_AAA(const Vector &val, const Vector &pt,
   {
      // select next support point
      int idx = 0;
-      real_t tmp_max = 0;
+      double tmp_max = 0;
      for (int j = 0; j < size; j++)
      {
-         real_t tmp = abs(val(j)-R(j));
+         double tmp = abs(val(j)-R(j));
         if (tmp > tmp_max)
         {
            tmp_max = tmp;
@@ -98,7 +98,7 @@ void RationalApproximation_AAA(const Vector &val, const Vector &pt,
      J.DeleteFirst(idx);

      // next column in Cauchy matrix
-      Array<real_t> C_tmp(size);
+      Array<double> C_tmp(size);
      for (int j = 0; j < size; j++)
      {
         C_tmp[j] = 1.0/(pt(j)-pt(idx));
@@ -173,7 +173,7 @@ void RationalApproximation_AAA(const Vector &val, const Vector &pt,

    See pg. A1501 of Nakatsukasa et al. [1]. */
 void ComputePolesAndZeros(const Vector &z, const Vector &f, const Vector &w,
-                          Array<real_t> & poles, Array<real_t> & zeros, real_t &scale)
+                          Array<double> & poles, Array<double> & zeros, double &scale)
 {
   // Initialization
   poles.SetSize(0);
@@ -242,8 +242,8 @@ void ComputePolesAndZeros(const Vector &z, const Vector &f, const Vector &w,
    @param[in]  zeros   Array of zeros
    @param[in]  scale   Scaling constant
    @param[out] coeffs  Coefficients c_i */
-void PartialFractionExpansion(real_t scale, Array<real_t> & poles,
-                              Array<real_t> & zeros, Array<real_t> & coeffs)
+void PartialFractionExpansion(double scale, Array<double> & poles,
+                              Array<double> & zeros, Array<double> & coeffs)
 {
   int psize = poles.Size();
   int zsize = zeros.Size();
@@ -259,13 +259,13 @@ void PartialFractionExpansion(real_t scale, Array<real_t> & poles,

   for (int i=0; i<psize; i++)
   {
-      real_t tmp_numer=1.0;
+      double tmp_numer=1.0;
      for (int j=0; j<zsize; j++)
      {
         tmp_numer *= poles[i]-zeros[j];
      }

-      real_t tmp_denom=1.0;
+      double tmp_denom=1.0;
      for (int k=0; k<psize; k++)
      {
         if (k != i) { tmp_denom *= poles[i]-poles[k]; }
@@ -292,10 +292,10 @@ void PartialFractionExpansion(real_t scale, Array<real_t> & poles,
           @a alpha != 0.99, then @a alpha = 0.5 is used by default.

   See pg. A1501 of Nakatsukasa et al. [1]. */
-void ComputePartialFractionApproximation(real_t & alpha,
-                                         Array<real_t> & coeffs, Array<real_t> & poles,
-                                         real_t lmax = 1000.,
-                                         real_t tol=1e-10, int npoints = 1000,
+void ComputePartialFractionApproximation(double & alpha,
+                                         Array<double> & coeffs, Array<double> & poles,
+                                         double lmax = 1000.,
+                                         double tol=1e-10, int npoints = 1000,
                                         int max_order = 100)
 {
   MFEM_VERIFY(alpha < 1., "alpha must be less than 1");
@@ -320,26 +320,26 @@ void ComputePartialFractionApproximation(real_t & alpha,
            << "\nThe default is alpha = 0.5.\n" << string(80, '=') << "\n"
            << endl;
   }
-   const real_t eps = std::numeric_limits<real_t>::epsilon();
+   const double eps = std::numeric_limits<double>::epsilon();

   if (abs(alpha - 0.33) < eps)
   {
-      coeffs = Array<real_t> ({1.821898e+03, 9.101221e+01, 2.650611e+01,
+      coeffs = Array<double> ({1.821898e+03, 9.101221e+01, 2.650611e+01,
                               1.174937e+01, 6.140444e+00, 3.441713e+00,
                               1.985735e+00, 1.162634e+00, 6.891560e-01,
                               4.111574e-01, 2.298736e-01});
-      poles = Array<real_t> ({-4.155583e+04, -2.956285e+03, -8.331715e+02,
+      poles = Array<double> ({-4.155583e+04, -2.956285e+03, -8.331715e+02,
                              -3.139332e+02, -1.303448e+02, -5.563385e+01,
                              -2.356255e+01, -9.595516e+00, -3.552160e+00,
                              -1.032136e+00, -1.241480e-01});
   }
   else if (abs(alpha - 0.99) < eps)
   {
-      coeffs = Array<real_t>({2.919591e-02, 1.419750e-02, 1.065798e-02,
+      coeffs = Array<double>({2.919591e-02, 1.419750e-02, 1.065798e-02,
                              9.395094e-03, 8.915329e-03, 8.822991e-03,
                              9.058247e-03, 9.814521e-03, 1.180396e-02,
                              1.834554e-02, 9.840482e-01});
-      poles = Array<real_t> ({-1.069683e+04, -1.769370e+03, -5.718374e+02,
+      poles = Array<double> ({-1.069683e+04, -1.769370e+03, -5.718374e+02,
                              -2.242095e+02, -9.419132e+01, -4.031012e+01,
                              -1.701525e+01, -6.810088e+00, -2.382810e+00,
                              -5.700059e-01, -1.384324e-03});
@@ -350,11 +350,11 @@ void ComputePartialFractionApproximation(real_t & alpha,
      {
         alpha = 0.5;
      }
-      coeffs = Array<real_t>({2.290262e+02, 2.641819e+01, 1.005566e+01,
+      coeffs = Array<double>({2.290262e+02, 2.641819e+01, 1.005566e+01,
                              5.390411e+00, 3.340725e+00, 2.211205e+00,
                              1.508883e+00, 1.049474e+00, 7.462709e-01,
                              5.482686e-01, 4.232510e-01, 3.578967e-01});
-      poles = Array<real_t>({-3.168211e+04, -3.236077e+03, -9.868287e+02,
+      poles = Array<double>({-3.168211e+04, -3.236077e+03, -9.868287e+02,
                             -3.945597e+02, -1.738889e+02, -7.925178e+01,
                             -3.624992e+01, -1.629196e+01, -6.982956e+00,
                             -2.679984e+00, -7.782607e-01, -7.649166e-02});
@@ -372,15 +372,15 @@ void ComputePartialFractionApproximation(real_t & alpha,

   Vector x(npoints);
   Vector val(npoints);
-   real_t dx = lmax / (real_t)(npoints-1);
+   double dx = lmax / (double)(npoints-1);
   for (int i = 0; i<npoints; i++)
   {
-      x(i) = dx * (real_t)i;
+      x(i) = dx * (double)i;
      val(i) = pow(x(i),1.-alpha);
   }

   // Apply triple-A algorithm to f(x) = x^{1-a}
-   Array<real_t> z, f;
+   Array<double> z, f;
   Vector w;
   RationalApproximation_AAA(val,x,z,f,w,tol,max_order);

@@ -389,8 +389,8 @@ void ComputePartialFractionApproximation(real_t & alpha,
   vecf.SetDataAndSize(f.GetData(), f.Size());

   // Compute poles and zeros for RA of f(x) = x^{1-a}
-   real_t scale;
-   Array<real_t> zeros;
+   double scale;
+   Array<double> zeros;
   ComputePolesAndZeros(vecz, vecf, w, poles, zeros, scale);

   // Remove the zero at x=0, thus, delivering a RA for f(x) = x^{-a}
@@ -96,7 +96,7 @@ int main(int argc, char *argv[])
   const char *mesh_file = "../data/star.mesh";
   int order = 1;
   int num_refs = 3;
-   real_t alpha = 0.5;
+   double alpha = 0.5;
   bool visualization = true;
   bool verification = false;

@@ -127,17 +127,13 @@ int main(int argc, char *argv[])
      args.PrintOptions(cout);
   }

-#ifdef MFEM_USE_SINGLE
-   MFEM_ABORT("This example is not supported in single precision.");
-#endif
-
-   Array<real_t> coeffs, poles;
+   Array<double> coeffs, poles;
   int progress_steps = 1;

   // 2. Compute the rational expansion coefficients that define the
   //    integer-order PDEs.
   const int power_of_laplace = floor(alpha);
-   real_t exponent_to_approximate = alpha - power_of_laplace;
+   double exponent_to_approximate = alpha - power_of_laplace;
   bool integer_order = false;
   // Check if alpha is an integer or not.
   if (abs(exponent_to_approximate) > 1e-12)
@@ -197,7 +193,7 @@ int main(int argc, char *argv[])
   // 7. Define diffusion coefficient, load, and solution GridFunction.
   auto func = [&alpha](const Vector &x)
   {
-      real_t val = 1.0;
+      double val = 1.0;
      for (int i=0; i<x.Size(); i++)
      {
         val *= sin(M_PI*x(i));
@@ -402,7 +398,7 @@ int main(int argc, char *argv[])
   {
      auto solution = [] (const Vector &x)
      {
-         real_t val = 1.0;
+         double val = 1.0;
         for (int i=0; i<x.Size(); i++)
         {
            val *= sin(M_PI*x(i));
@@ -410,7 +406,7 @@ int main(int argc, char *argv[])
         return val;
      };
      FunctionCoefficient sol(solution);
-      real_t l2_error = u.ComputeL2Error(sol);
+      double l2_error = u.ComputeL2Error(sol);

      if (Mpi::Root())
      {
@@ -69,7 +69,7 @@ int main(int argc, char *argv[])
   Array<int> jn_zero_attr;
   int ref_levels = 1;
   int order = 1;
-   real_t delta_const = 1e-6;
+   double delta_const = 1e-6;
   bool mixed = true;
   bool static_cond = false;
   const char *device_config = "cpu";
@@ -73,7 +73,7 @@ int main(int argc, char *argv[])
   int ser_ref_levels = 1;
   int par_ref_levels = 1;
   int order = 1;
-   real_t delta_const = 1e-6;
+   double delta_const = 1e-6;
   bool mixed = true;
   bool static_cond = false;
   bool pa = false;
@@ -55,9 +55,9 @@
 using namespace std;
 using namespace mfem;

-static real_t mu_ = 1.0;
-static real_t epsilon_ = 1.0;
-static real_t sigma_ = 2.0;
+static double mu_ = 1.0;
+static double epsilon_ = 1.0;
+static double sigma_ = 2.0;

 void SetPortBC(int prob, int dim, int mode, ParGridFunction &port_bc);

@@ -77,9 +77,9 @@ int main(int argc, char *argv[])
   Array<int> port_bc_attr;
   int prob = 0;
   int mode = 1;
-   real_t freq = -1.0;
-   real_t omega = 2.0 * M_PI;
-   real_t a_coef = 0.0;
+   double freq = -1.0;
+   double omega = 2.0 * M_PI;
+   double a_coef = 0.0;
   bool herm_conv = true;
   bool slu_solver  = false;
   bool visualization = 1;
@@ -587,7 +587,7 @@ int main(int argc, char *argv[])
      int i = 0;
      while (sol_sock)
      {
-         real_t t = (real_t)(i % num_frames) / num_frames;
+         double t = (double)(i % num_frames) / num_frames;
         ostringstream oss;
         oss << "Harmonic Solution (t = " << t << " T)";

@@ -637,7 +637,7 @@ void ScalarWaveGuide(int mode, ParGridFunction &x)
   m.AddDomainIntegrator(new MassIntegrator);
   m.Assemble();
   // shift the eigenvalue corresponding to eliminated dofs to a large value
-   m.EliminateEssentialBCDiag(ess_bdr, numeric_limits<real_t>::min());
+   m.EliminateEssentialBCDiag(ess_bdr, numeric_limits<double>::min());
   m.Finalize();

   HypreParMatrix *A = a.ParallelAssemble();
@@ -694,7 +694,7 @@ void VectorWaveGuide(int mode, ParGridFunction &x)
   m.AddDomainIntegrator(new VectorFEMassIntegrator);
   m.Assemble();
   // shift the eigenvalue corresponding to eliminated dofs to a large value
-   m.EliminateEssentialBCDiag(ess_bdr, numeric_limits<real_t>::min());
+   m.EliminateEssentialBCDiag(ess_bdr, numeric_limits<double>::min());
   m.Finalize();

   HypreParMatrix *A = a.ParallelAssemble();
@@ -37,8 +37,8 @@
 using namespace std;
 using namespace mfem;

-real_t spherical_obstacle(const Vector &pt);
-real_t exact_solution_obstacle(const Vector &pt);
+double spherical_obstacle(const Vector &pt);
+double exact_solution_obstacle(const Vector &pt);
 void exact_solution_gradient_obstacle(const Vector &pt, Vector &grad);

 class LogarithmGridFunctionCoefficient : public Coefficient
@@ -46,14 +46,14 @@ class LogarithmGridFunctionCoefficient : public Coefficient
 protected:
   GridFunction *u; // grid function
   Coefficient *obstacle;
-   real_t min_val;
+   double min_val;

 public:
   LogarithmGridFunctionCoefficient(GridFunction &u_, Coefficient &obst_,
-                                    real_t min_val_=-36)
+                                    double min_val_=-36)
      : u(&u_), obstacle(&obst_), min_val(min_val_) { }

-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip);
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip);
 };

 class ExponentialGridFunctionCoefficient : public Coefficient
@@ -61,15 +61,15 @@ class ExponentialGridFunctionCoefficient : public Coefficient
 protected:
   GridFunction *u;
   Coefficient *obstacle;
-   real_t min_val;
-   real_t max_val;
+   double min_val;
+   double max_val;

 public:
   ExponentialGridFunctionCoefficient(GridFunction &u_, Coefficient &obst_,
-                                      real_t min_val_=0.0, real_t max_val_=1e6)
+                                      double min_val_=0.0, double max_val_=1e6)
      : u(&u_), obstacle(&obst_), min_val(min_val_), max_val(max_val_) { }

-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip);
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip);
 };

 int main(int argc, char *argv[])
@@ -78,8 +78,8 @@ int main(int argc, char *argv[])
   int order = 1;
   int max_it = 10;
   int ref_levels = 3;
-   real_t alpha = 1.0;
-   real_t tol = 1e-5;
+   double alpha = 1.0;
+   double tol = 1e-5;
   bool visualization = true;

   OptionsParser args(argc, argv);
@@ -124,7 +124,7 @@ int main(int argc, char *argv[])

   // 3C. Rescale the domain to a unit circle (radius = 1).
   GridFunction *nodes = mesh.GetNodes();
-   real_t scale = 2*sqrt(2);
+   double scale = 2*sqrt(2);
   *nodes /= scale;

   // 4. Define the necessary finite element spaces on the mesh.
@@ -159,8 +159,8 @@ int main(int argc, char *argv[])
   // 6. Define an initial guess for the solution.
   auto IC_func = [](const Vector &x)
   {
-      real_t r0 = 1.0;
-      real_t rr = 0.0;
+      double r0 = 1.0;
+      double rr = 0.0;
      for (int i=0; i<x.Size(); i++)
      {
         rr += x(i)*x(i);
@@ -211,7 +211,7 @@ int main(int argc, char *argv[])
   // 10. Iterate
   int k;
   int total_iterations = 0;
-   real_t increment_u = 0.1;
+   double increment_u = 0.1;
   for (k = 0; k < max_it; k++)
   {
      GridFunction u_tmp(&H1fes);
@@ -300,10 +300,10 @@ int main(int argc, char *argv[])
         delta_psi_gf.MakeRef(&L2fes, x.GetBlock(1), 0);

         u_tmp -= u_gf;
-         real_t Newton_update_size = u_tmp.ComputeL2Error(zero);
+         double Newton_update_size = u_tmp.ComputeL2Error(zero);
         u_tmp = u_gf;

-         real_t gamma = 1.0;
+         double gamma = 1.0;
         delta_psi_gf *= gamma;
         psi_gf += delta_psi_gf;

@@ -337,7 +337,7 @@ int main(int argc, char *argv[])
         break;
      }

-      real_t H1_error = u_gf.ComputeH1Error(&exact_coef,&exact_grad_coef);
+      double H1_error = u_gf.ComputeH1Error(&exact_coef,&exact_grad_coef);
      mfem::out << "H1-error  (|| u - uₕᵏ||)       = " << H1_error << endl;

   }
@@ -362,13 +362,13 @@ int main(int argc, char *argv[])
   }

   {
-      real_t L2_error = u_gf.ComputeL2Error(exact_coef);
-      real_t H1_error = u_gf.ComputeH1Error(&exact_coef,&exact_grad_coef);
+      double L2_error = u_gf.ComputeL2Error(exact_coef);
+      double H1_error = u_gf.ComputeH1Error(&exact_coef,&exact_grad_coef);

      ExponentialGridFunctionCoefficient u_alt_cf(psi_gf,obstacle);
      GridFunction u_alt_gf(&L2fes);
      u_alt_gf.ProjectCoefficient(u_alt_cf);
-      real_t L2_error_alt = u_alt_gf.ComputeL2Error(exact_coef);
+      double L2_error_alt = u_alt_gf.ComputeL2Error(exact_coef);

      mfem::out << "\n Final L2-error (|| u - uₕ||)          = " << L2_error <<
                endl;
@@ -380,35 +380,35 @@ int main(int argc, char *argv[])
   return 0;
 }

-real_t LogarithmGridFunctionCoefficient::Eval(ElementTransformation &T,
+double LogarithmGridFunctionCoefficient::Eval(ElementTransformation &T,
                                              const IntegrationPoint &ip)
 {
   MFEM_ASSERT(u != NULL, "grid function is not set");

-   real_t val = u->GetValue(T, ip) - obstacle->Eval(T, ip);
+   double val = u->GetValue(T, ip) - obstacle->Eval(T, ip);
   return max(min_val, log(val));
 }

-real_t ExponentialGridFunctionCoefficient::Eval(ElementTransformation &T,
+double ExponentialGridFunctionCoefficient::Eval(ElementTransformation &T,
                                                const IntegrationPoint &ip)
 {
   MFEM_ASSERT(u != NULL, "grid function is not set");

-   real_t val = u->GetValue(T, ip);
+   double val = u->GetValue(T, ip);
   return min(max_val, max(min_val, exp(val) + obstacle->Eval(T, ip)));
 }

-real_t spherical_obstacle(const Vector &pt)
+double spherical_obstacle(const Vector &pt)
 {
-   real_t x = pt(0), y = pt(1);
-   real_t r = sqrt(x*x + y*y);
-   real_t r0 = 0.5;
-   real_t beta = 0.9;
+   double x = pt(0), y = pt(1);
+   double r = sqrt(x*x + y*y);
+   double r0 = 0.5;
+   double beta = 0.9;

-   real_t b = r0*beta;
-   real_t tmp = sqrt(r0*r0 - b*b);
-   real_t B = tmp + b*b/tmp;
-   real_t C = -b/tmp;
+   double b = r0*beta;
+   double tmp = sqrt(r0*r0 - b*b);
+   double B = tmp + b*b/tmp;
+   double C = -b/tmp;

   if (r > b)
   {
@@ -420,13 +420,13 @@ real_t spherical_obstacle(const Vector &pt)
   }
 }

-real_t exact_solution_obstacle(const Vector &pt)
+double exact_solution_obstacle(const Vector &pt)
 {
-   real_t x = pt(0), y = pt(1);
-   real_t r = sqrt(x*x + y*y);
-   real_t r0 = 0.5;
-   real_t a =  0.348982574111686;
-   real_t A = -0.340129705945858;
+   double x = pt(0), y = pt(1);
+   double r = sqrt(x*x + y*y);
+   double r0 = 0.5;
+   double a =  0.348982574111686;
+   double A = -0.340129705945858;

   if (r > a)
   {
@@ -440,11 +440,11 @@ real_t exact_solution_obstacle(const Vector &pt)

 void exact_solution_gradient_obstacle(const Vector &pt, Vector &grad)
 {
-   real_t x = pt(0), y = pt(1);
-   real_t r = sqrt(x*x + y*y);
-   real_t r0 = 0.5;
-   real_t a =  0.348982574111686;
-   real_t A = -0.340129705945858;
+   double x = pt(0), y = pt(1);
+   double r = sqrt(x*x + y*y);
+   double r0 = 0.5;
+   double a =  0.348982574111686;
+   double A = -0.340129705945858;

   if (r > a)
   {
@@ -37,8 +37,8 @@
 using namespace std;
 using namespace mfem;

-real_t spherical_obstacle(const Vector &pt);
-real_t exact_solution_obstacle(const Vector &pt);
+double spherical_obstacle(const Vector &pt);
+double exact_solution_obstacle(const Vector &pt);
 void exact_solution_gradient_obstacle(const Vector &pt, Vector &grad);

 class LogarithmGridFunctionCoefficient : public Coefficient
@@ -46,14 +46,14 @@ class LogarithmGridFunctionCoefficient : public Coefficient
 protected:
   GridFunction *u; // grid function
   Coefficient *obstacle;
-   real_t min_val;
+   double min_val;

 public:
   LogarithmGridFunctionCoefficient(GridFunction &u_, Coefficient &obst_,
-                                    real_t min_val_=-36)
+                                    double min_val_=-36)
      : u(&u_), obstacle(&obst_), min_val(min_val_) { }

-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip);
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip);
 };

 class ExponentialGridFunctionCoefficient : public Coefficient
@@ -61,15 +61,15 @@ class ExponentialGridFunctionCoefficient : public Coefficient
 protected:
   GridFunction *u;
   Coefficient *obstacle;
-   real_t min_val;
-   real_t max_val;
+   double min_val;
+   double max_val;

 public:
   ExponentialGridFunctionCoefficient(GridFunction &u_, Coefficient &obst_,
-                                      real_t min_val_=0.0, real_t max_val_=1e6)
+                                      double min_val_=0.0, double max_val_=1e6)
      : u(&u_), obstacle(&obst_), min_val(min_val_), max_val(max_val_) { }

-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip);
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip);
 };

 int main(int argc, char *argv[])
@@ -84,8 +84,8 @@ int main(int argc, char *argv[])
   int order = 1;
   int max_it = 10;
   int ref_levels = 3;
-   real_t alpha = 1.0;
-   real_t tol = 1e-5;
+   double alpha = 1.0;
+   double tol = 1e-5;
   bool visualization = true;

   OptionsParser args(argc, argv);
@@ -136,7 +136,7 @@ int main(int argc, char *argv[])

   // 3C. Rescale the domain to a unit circle (radius = 1).
   GridFunction *nodes = mesh.GetNodes();
-   real_t scale = 2*sqrt(2);
+   double scale = 2*sqrt(2);
   *nodes /= scale;

   ParMesh pmesh(MPI_COMM_WORLD, mesh);
@@ -192,8 +192,8 @@ int main(int argc, char *argv[])
   // 6. Define an initial guess for the solution.
   auto IC_func = [](const Vector &x)
   {
-      real_t r0 = 1.0;
-      real_t rr = 0.0;
+      double r0 = 1.0;
+      double rr = 0.0;
      for (int i=0; i<x.Size(); i++)
      {
         rr += x(i)*x(i);
@@ -243,7 +243,7 @@ int main(int argc, char *argv[])
   // 10. Iterate
   int k;
   int total_iterations = 0;
-   real_t increment_u = 0.1;
+   double increment_u = 0.1;
   for (k = 0; k < max_it; k++)
   {
      ParGridFunction u_tmp(&H1fes);
@@ -346,10 +346,10 @@ int main(int argc, char *argv[])
         delta_psi_gf.SetFromTrueDofs(tx.GetBlock(1));

         u_tmp -= u_gf;
-         real_t Newton_update_size = u_tmp.ComputeL2Error(zero);
+         double Newton_update_size = u_tmp.ComputeL2Error(zero);
         u_tmp = u_gf;

-         real_t gamma = 1.0;
+         double gamma = 1.0;
         delta_psi_gf *= gamma;
         psi_gf += delta_psi_gf;

@@ -391,7 +391,7 @@ int main(int argc, char *argv[])
         break;
      }

-      real_t H1_error = u_gf.ComputeH1Error(&exact_coef,&exact_grad_coef);
+      double H1_error = u_gf.ComputeH1Error(&exact_coef,&exact_grad_coef);
      if (myid == 0)
      {
         mfem::out << "H1-error  (|| u - uₕᵏ||)       = " << H1_error << endl;
@@ -423,13 +423,13 @@ int main(int argc, char *argv[])
   }

   {
-      real_t L2_error = u_gf.ComputeL2Error(exact_coef);
-      real_t H1_error = u_gf.ComputeH1Error(&exact_coef,&exact_grad_coef);
+      double L2_error = u_gf.ComputeL2Error(exact_coef);
+      double H1_error = u_gf.ComputeH1Error(&exact_coef,&exact_grad_coef);

      ExponentialGridFunctionCoefficient u_alt_cf(psi_gf,obstacle);
      ParGridFunction u_alt_gf(&L2fes);
      u_alt_gf.ProjectCoefficient(u_alt_cf);
-      real_t L2_error_alt = u_alt_gf.ComputeL2Error(exact_coef);
+      double L2_error_alt = u_alt_gf.ComputeL2Error(exact_coef);

      if (myid == 0)
      {
@@ -444,35 +444,35 @@ int main(int argc, char *argv[])
   return 0;
 }

-real_t LogarithmGridFunctionCoefficient::Eval(ElementTransformation &T,
+double LogarithmGridFunctionCoefficient::Eval(ElementTransformation &T,
                                              const IntegrationPoint &ip)
 {
   MFEM_ASSERT(u != NULL, "grid function is not set");

-   real_t val = u->GetValue(T, ip) - obstacle->Eval(T, ip);
+   double val = u->GetValue(T, ip) - obstacle->Eval(T, ip);
   return max(min_val, log(val));
 }

-real_t ExponentialGridFunctionCoefficient::Eval(ElementTransformation &T,
+double ExponentialGridFunctionCoefficient::Eval(ElementTransformation &T,
                                                const IntegrationPoint &ip)
 {
   MFEM_ASSERT(u != NULL, "grid function is not set");

-   real_t val = u->GetValue(T, ip);
+   double val = u->GetValue(T, ip);
   return min(max_val, max(min_val, exp(val) + obstacle->Eval(T, ip)));
 }

-real_t spherical_obstacle(const Vector &pt)
+double spherical_obstacle(const Vector &pt)
 {
-   real_t x = pt(0), y = pt(1);
-   real_t r = sqrt(x*x + y*y);
-   real_t r0 = 0.5;
-   real_t beta = 0.9;
+   double x = pt(0), y = pt(1);
+   double r = sqrt(x*x + y*y);
+   double r0 = 0.5;
+   double beta = 0.9;

-   real_t b = r0*beta;
-   real_t tmp = sqrt(r0*r0 - b*b);
-   real_t B = tmp + b*b/tmp;
-   real_t C = -b/tmp;
+   double b = r0*beta;
+   double tmp = sqrt(r0*r0 - b*b);
+   double B = tmp + b*b/tmp;
+   double C = -b/tmp;

   if (r > b)
   {
@@ -484,13 +484,13 @@ real_t spherical_obstacle(const Vector &pt)
   }
 }

-real_t exact_solution_obstacle(const Vector &pt)
+double exact_solution_obstacle(const Vector &pt)
 {
-   real_t x = pt(0), y = pt(1);
-   real_t r = sqrt(x*x + y*y);
-   real_t r0 = 0.5;
-   real_t a =  0.348982574111686;
-   real_t A = -0.340129705945858;
+   double x = pt(0), y = pt(1);
+   double r = sqrt(x*x + y*y);
+   double r0 = 0.5;
+   double a =  0.348982574111686;
+   double A = -0.340129705945858;

   if (r > a)
   {
@@ -504,11 +504,11 @@ real_t exact_solution_obstacle(const Vector &pt)

 void exact_solution_gradient_obstacle(const Vector &pt, Vector &grad)
 {
-   real_t x = pt(0), y = pt(1);
-   real_t r = sqrt(x*x + y*y);
-   real_t r0 = 0.5;
-   real_t a =  0.348982574111686;
-   real_t A = -0.340129705945858;
+   double x = pt(0), y = pt(1);
+   double r = sqrt(x*x + y*y);
+   double r0 = 0.5;
+   double a =  0.348982574111686;
+   double A = -0.340129705945858;

   if (r > a)
   {
@@ -67,9 +67,9 @@ using namespace mfem;
 * @param target_volume θ vol(Ω)
 * @param tol Newton iteration tolerance
 * @param max_its Newton maximum iteration number
- * @return real_t Final volume, ∫_Ω sigmoid(ψ)
+ * @return double Final volume, ∫_Ω sigmoid(ψ)
 */
-real_t proj(GridFunction &psi, real_t target_volume, real_t tol=1e-12,
+double proj(GridFunction &psi, double target_volume, double tol=1e-12,
            int max_its=10)
 {
   MappedGridFunctionCoefficient sigmoid_psi(&psi, sigmoid);
@@ -84,12 +84,12 @@ real_t proj(GridFunction &psi, real_t target_volume, real_t tol=1e-12,
   for (int k=0; k<max_its; k++) // Newton iteration
   {
      int_sigmoid_psi.Assemble(); // Recompute f(c) with updated ψ
-      const real_t f = int_sigmoid_psi.Sum() - target_volume;
+      const double f = int_sigmoid_psi.Sum() - target_volume;

      int_der_sigmoid_psi.Assemble(); // Recompute df(c) with updated ψ
-      const real_t df = int_der_sigmoid_psi.Sum();
+      const double df = int_der_sigmoid_psi.Sum();

-      const real_t dc = -f/df;
+      const double dc = -f/df;
      psi += dc;
      if (abs(dc) < tol) { done = true; break; }
   }
@@ -179,15 +179,15 @@ int main(int argc, char *argv[])
   // 1. Parse command-line options.
   int ref_levels = 5;
   int order = 2;
-   real_t alpha = 1.0;
-   real_t epsilon = 0.01;
-   real_t vol_fraction = 0.5;
+   double alpha = 1.0;
+   double epsilon = 0.01;
+   double vol_fraction = 0.5;
   int max_it = 1e3;
-   real_t itol = 1e-1;
-   real_t ntol = 1e-4;
-   real_t rho_min = 1e-6;
-   real_t lambda = 1.0;
-   real_t mu = 1.0;
+   double itol = 1e-1;
+   double ntol = 1e-4;
+   double rho_min = 1e-6;
+   double lambda = 1.0;
+   double mu = 1.0;
   bool glvis_visualization = true;
   bool paraview_output = false;

@@ -239,8 +239,8 @@ int main(int argc, char *argv[])
      Array<int> vertices;
      be->GetVertices(vertices);

-      real_t * coords1 = mesh.GetVertex(vertices[0]);
-      real_t * coords2 = mesh.GetVertex(vertices[1]);
+      double * coords1 = mesh.GetVertex(vertices[0]);
+      double * coords2 = mesh.GetVertex(vertices[1]);

      Vector center(2);
      center(0) = 0.5*(coords1[0] + coords2[0]);
@@ -312,7 +312,7 @@ int main(int argc, char *argv[])
   ElasticitySolver->SetupFEM();
   Vector center(2); center(0) = 2.9; center(1) = 0.5;
   Vector force(2); force(0) = 0.0; force(1) = -1.0;
-   real_t r = 0.05;
+   double r = 0.05;
   VolumeForceCoefficient vforce_cf(r,center,force);
   ElasticitySolver->SetRHSCoefficient(&vforce_cf);
   ElasticitySolver->SetEssentialBoundary(ess_bdr);
@@ -353,8 +353,8 @@ int main(int argc, char *argv[])
   LinearForm vol_form(&control_fes);
   vol_form.AddDomainIntegrator(new DomainLFIntegrator(one));
   vol_form.Assemble();
-   real_t domain_volume = vol_form(onegf);
-   const real_t target_volume = domain_volume * vol_fraction;
+   double domain_volume = vol_form(onegf);
+   const double target_volume = domain_volume * vol_fraction;

   // 10. Connect to GLVis. Prepare for VisIt output.
   char vishost[] = "localhost";
@@ -385,7 +385,7 @@ int main(int argc, char *argv[])
   // 11. Iterate:
   for (int k = 1; k <= max_it; k++)
   {
-      if (k > 1) { alpha *= ((real_t) k) / ((real_t) k-1); }
+      if (k > 1) { alpha *= ((double) k) / ((double) k-1); }

      mfem::out << "\nStep = " << k << std::endl;

@@ -422,14 +422,14 @@ int main(int argc, char *argv[])

      // Step 5 - Update design variable ψ ← proj(ψ - αG)
      psi.Add(-alpha, grad);
-      const real_t material_volume = proj(psi, target_volume);
+      const double material_volume = proj(psi, target_volume);

      // Compute ||ρ - ρ_old|| in control fes.
-      real_t norm_increment = zerogf.ComputeL1Error(succ_diff_rho);
-      real_t norm_reduced_gradient = norm_increment/alpha;
+      double norm_increment = zerogf.ComputeL1Error(succ_diff_rho);
+      double norm_reduced_gradient = norm_increment/alpha;
      psi_old = psi;

-      real_t compliance = (*(ElasticitySolver->GetLinearForm()))(u);
+      double compliance = (*(ElasticitySolver->GetLinearForm()))(u);
      mfem::out << "norm of the reduced gradient = " << norm_reduced_gradient <<
                std::endl;
      mfem::out << "norm of the increment = " << norm_increment << endl;
@@ -449,7 +449,7 @@ int main(int argc, char *argv[])
      {
         rho_gf.ProjectCoefficient(rho);
         paraview_dc.SetCycle(k);
-         paraview_dc.SetTime((real_t)k);
+         paraview_dc.SetTime((double)k);
         paraview_dc.Save();
      }

@@ -9,15 +9,15 @@ namespace mfem
 {

 /// @brief Inverse sigmoid function
-real_t inv_sigmoid(real_t x)
+double inv_sigmoid(double x)
 {
-   real_t tol = 1e-12;
-   x = std::min(std::max(tol,x), real_t(1.0)-tol);
+   double tol = 1e-12;
+   x = std::min(std::max(tol,x),1.0-tol);
   return std::log(x/(1.0-x));
 }

 /// @brief Sigmoid function
-real_t sigmoid(real_t x)
+double sigmoid(double x)
 {
   if (x >= 0)
   {
@@ -30,9 +30,9 @@ real_t sigmoid(real_t x)
 }

 /// @brief Derivative of sigmoid function
-real_t der_sigmoid(real_t x)
+double der_sigmoid(double x)
 {
-   real_t tmp = sigmoid(-x);
+   double tmp = sigmoid(-x);
   return tmp - std::pow(tmp,2);
 }

@@ -40,24 +40,24 @@ real_t der_sigmoid(real_t x)
 class MappedGridFunctionCoefficient : public GridFunctionCoefficient
 {
 protected:
-   std::function<real_t(const real_t)> fun; // f:R → R
+   std::function<double(const double)> fun; // f:R → R
 public:
   MappedGridFunctionCoefficient()
      :GridFunctionCoefficient(),
-       fun([](real_t x) {return x;}) {}
+       fun([](double x) {return x;}) {}
   MappedGridFunctionCoefficient(const GridFunction *gf,
-                                 std::function<real_t(const real_t)> fun_,
+                                 std::function<double(const double)> fun_,
                                 int comp=1)
      :GridFunctionCoefficient(gf, comp),
       fun(fun_) {}


-   virtual real_t Eval(ElementTransformation &T,
+   virtual double Eval(ElementTransformation &T,
                       const IntegrationPoint &ip)
   {
      return fun(GridFunctionCoefficient::Eval(T, ip));
   }
-   void SetFunction(std::function<real_t(const real_t)> fun_) { fun = fun_; }
+   void SetFunction(std::function<double(const double)> fun_) { fun = fun_; }
 };


@@ -67,30 +67,30 @@ class DiffMappedGridFunctionCoefficient : public GridFunctionCoefficient
 protected:
   const GridFunction *OtherGridF;
   GridFunctionCoefficient OtherGridF_cf;
-   std::function<real_t(const real_t)> fun; // f:R → R
+   std::function<double(const double)> fun; // f:R → R
 public:
   DiffMappedGridFunctionCoefficient()
      :GridFunctionCoefficient(),
       OtherGridF(nullptr),
       OtherGridF_cf(),
-       fun([](real_t x) {return x;}) {}
+       fun([](double x) {return x;}) {}
   DiffMappedGridFunctionCoefficient(const GridFunction *gf,
                                     const GridFunction *other_gf,
-                                     std::function<real_t(const real_t)> fun_,
+                                     std::function<double(const double)> fun_,
                                     int comp=1)
      :GridFunctionCoefficient(gf, comp),
       OtherGridF(other_gf),
       OtherGridF_cf(OtherGridF),
       fun(fun_) {}

-   virtual real_t Eval(ElementTransformation &T,
+   virtual double Eval(ElementTransformation &T,
                       const IntegrationPoint &ip)
   {
-      const real_t value1 = fun(GridFunctionCoefficient::Eval(T, ip));
-      const real_t value2 = fun(OtherGridF_cf.Eval(T, ip));
+      const double value1 = fun(GridFunctionCoefficient::Eval(T, ip));
+      const double value2 = fun(OtherGridF_cf.Eval(T, ip));
      return value1 - value2;
   }
-   void SetFunction(std::function<real_t(const real_t)> fun_) { fun = fun_; }
+   void SetFunction(std::function<double(const double)> fun_) { fun = fun_; }
 };

 /// @brief Solid isotropic material penalization (SIMP) coefficient
@@ -98,20 +98,20 @@ class SIMPInterpolationCoefficient : public Coefficient
 {
 protected:
   GridFunction *rho_filter;
-   real_t min_val;
-   real_t max_val;
-   real_t exponent;
+   double min_val;
+   double max_val;
+   double exponent;

 public:
-   SIMPInterpolationCoefficient(GridFunction *rho_filter_, real_t min_val_= 1e-6,
-                                real_t max_val_ = 1.0, real_t exponent_ = 3)
+   SIMPInterpolationCoefficient(GridFunction *rho_filter_, double min_val_= 1e-6,
+                                double max_val_ = 1.0, double exponent_ = 3)
      : rho_filter(rho_filter_), min_val(min_val_), max_val(max_val_),
        exponent(exponent_) { }

-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip)
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip)
   {
-      real_t val = rho_filter->GetValue(T, ip);
-      real_t coeff = min_val + pow(val,exponent)*(max_val-min_val);
+      double val = rho_filter->GetValue(T, ip);
+      double coeff = min_val + pow(val,exponent)*(max_val-min_val);
      return coeff;
   }
 };
@@ -126,13 +126,13 @@ protected:
   GridFunction *u = nullptr; // displacement
   GridFunction *rho_filter = nullptr; // filter density
   DenseMatrix grad; // auxiliary matrix, used in Eval
-   real_t exponent;
-   real_t rho_min;
+   double exponent;
+   double rho_min;

 public:
   StrainEnergyDensityCoefficient(Coefficient *lambda_, Coefficient *mu_,
-                                  GridFunction * u_, GridFunction * rho_filter_, real_t rho_min_=1e-6,
-                                  real_t exponent_ = 3.0)
+                                  GridFunction * u_, GridFunction * rho_filter_, double rho_min_=1e-6,
+                                  double exponent_ = 3.0)
      : lambda(lambda_), mu(mu_),  u(u_), rho_filter(rho_filter_),
        exponent(exponent_), rho_min(rho_min_)
   {
@@ -142,13 +142,13 @@ public:
      MFEM_ASSERT(rho_filter, "density field is not set");
   }

-   virtual real_t Eval(ElementTransformation &T, const IntegrationPoint &ip)
+   virtual double Eval(ElementTransformation &T, const IntegrationPoint &ip)
   {
-      real_t L = lambda->Eval(T, ip);
-      real_t M = mu->Eval(T, ip);
+      double L = lambda->Eval(T, ip);
+      double M = mu->Eval(T, ip);
      u->GetVectorGradient(T, grad);
-      real_t div_u = grad.Trace();
-      real_t density = L*div_u*div_u;
+      double div_u = grad.Trace();
+      double density = L*div_u*div_u;
      int dim = T.GetSpaceDim();
      for (int i=0; i<dim; i++)
      {
@@ -157,7 +157,7 @@ public:
            density += M*grad(i,j)*(grad(i,j)+grad(j,i));
         }
      }
-      real_t val = rho_filter->GetValue(T,ip);
+      double val = rho_filter->GetValue(T,ip);

      return -exponent * pow(val, exponent-1.0) * (1-rho_min) * density;
   }
@@ -167,11 +167,11 @@ public:
 class VolumeForceCoefficient : public VectorCoefficient
 {
 private:
-   real_t r;
+   double r;
   Vector center;
   Vector force;
 public:
-   VolumeForceCoefficient(real_t r_,Vector &  center_, Vector & force_) :
+   VolumeForceCoefficient(double r_,Vector &  center_, Vector & force_) :
      VectorCoefficient(center_.Size()), r(r_), center(center_), force(force_) { }

   using VectorCoefficient::Eval;
@@ -186,7 +186,7 @@ public:
         xx[i]=xx[i]-center[i];
      }

-      real_t cr=xx.Norml2();
+      double cr=xx.Norml2();
      V.SetSize(T.GetDimension());
      if (cr <= r)
      {
@@ -198,7 +198,7 @@ public:
      }
   }

-   void Set(real_t r_,Vector & center_, Vector & force_)
+   void Set(double r_,Vector & center_, Vector & force_)
   {
      r=r_;
      center = center_;
@@ -66,9 +66,9 @@ using namespace mfem;
 * @param target_volume θ vol(Ω)
 * @param tol Newton iteration tolerance
 * @param max_its Newton maximum iteration number
- * @return real_t Final volume, ∫_Ω sigmoid(ψ)
+ * @return double Final volume, ∫_Ω sigmoid(ψ)
 */
-real_t proj(ParGridFunction &psi, real_t target_volume, real_t tol=1e-12,
+double proj(ParGridFunction &psi, double target_volume, double tol=1e-12,
            int max_its=10)
 {
   MappedGridFunctionCoefficient sigmoid_psi(&psi, sigmoid);
@@ -83,17 +83,15 @@ real_t proj(ParGridFunction &psi, real_t target_volume, real_t tol=1e-12,
   for (int k=0; k<max_its; k++) // Newton iteration
   {
      int_sigmoid_psi.Assemble(); // Recompute f(c) with updated ψ
-      real_t f = int_sigmoid_psi.Sum();
-      MPI_Allreduce(MPI_IN_PLACE, &f, 1, MPITypeMap<real_t>::mpi_type,
-                    MPI_SUM, MPI_COMM_WORLD);
+      double f = int_sigmoid_psi.Sum();
+      MPI_Allreduce(MPI_IN_PLACE, &f, 1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
      f -= target_volume;

      int_der_sigmoid_psi.Assemble(); // Recompute df(c) with updated ψ
-      real_t df = int_der_sigmoid_psi.Sum();
-      MPI_Allreduce(MPI_IN_PLACE, &df, 1, MPITypeMap<real_t>::mpi_type,
-                    MPI_SUM, MPI_COMM_WORLD);
+      double df = int_der_sigmoid_psi.Sum();
+      MPI_Allreduce(MPI_IN_PLACE, &df, 1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);

-      const real_t dc = -f/df;
+      const double dc = -f/df;
      psi += dc;
      if (abs(dc) < tol) { done = true; break; }
   }
@@ -103,9 +101,9 @@ real_t proj(ParGridFunction &psi, real_t target_volume, real_t tol=1e-12,
                   "Result may not be accurate.");
   }
   int_sigmoid_psi.Assemble();
-   real_t material_volume = int_sigmoid_psi.Sum();
-   MPI_Allreduce(MPI_IN_PLACE, &material_volume, 1,
-                 MPITypeMap<real_t>::mpi_type, MPI_SUM, MPI_COMM_WORLD);
+   double material_volume = int_sigmoid_psi.Sum();
+   MPI_Allreduce(MPI_IN_PLACE, &material_volume, 1, MPI_DOUBLE, MPI_SUM,
+                 MPI_COMM_WORLD);
   return material_volume;
 }

@@ -192,15 +190,15 @@ int main(int argc, char *argv[])
   // 1. Parse command-line options.
   int ref_levels = 5;
   int order = 2;
-   real_t alpha = 1.0;
-   real_t epsilon = 0.01;
-   real_t vol_fraction = 0.5;
+   double alpha = 1.0;
+   double epsilon = 0.01;
+   double vol_fraction = 0.5;
   int max_it = 1e3;
-   real_t itol = 1e-1;
-   real_t ntol = 1e-4;
-   real_t rho_min = 1e-6;
-   real_t lambda = 1.0;
-   real_t mu = 1.0;
+   double itol = 1e-1;
+   double ntol = 1e-4;
+   double rho_min = 1e-6;
+   double lambda = 1.0;
+   double mu = 1.0;
   bool glvis_visualization = true;
   bool paraview_output = false;

@@ -260,8 +258,8 @@ int main(int argc, char *argv[])
      Array<int> vertices;
      be->GetVertices(vertices);

-      real_t * coords1 = mesh.GetVertex(vertices[0]);
-      real_t * coords2 = mesh.GetVertex(vertices[1]);
+      double * coords1 = mesh.GetVertex(vertices[0]);
+      double * coords2 = mesh.GetVertex(vertices[1]);

      Vector center(2);
      center(0) = 0.5*(coords1[0] + coords2[0]);
@@ -339,7 +337,7 @@ int main(int argc, char *argv[])
   ElasticitySolver->SetupFEM();
   Vector center(2); center(0) = 2.9; center(1) = 0.5;
   Vector force(2); force(0) = 0.0; force(1) = -1.0;
-   real_t r = 0.05;
+   double r = 0.05;
   VolumeForceCoefficient vforce_cf(r,center,force);
   ElasticitySolver->SetRHSCoefficient(&vforce_cf);
   ElasticitySolver->SetEssentialBoundary(ess_bdr);
@@ -380,8 +378,8 @@ int main(int argc, char *argv[])
   ParLinearForm vol_form(&control_fes);
   vol_form.AddDomainIntegrator(new DomainLFIntegrator(one));
   vol_form.Assemble();
-   real_t domain_volume = vol_form(onegf);
-   const real_t target_volume = domain_volume * vol_fraction;
+   double domain_volume = vol_form(onegf);
+   const double target_volume = domain_volume * vol_fraction;

   // 10. Connect to GLVis. Prepare for VisIt output.
   char vishost[] = "localhost";
@@ -412,7 +410,7 @@ int main(int argc, char *argv[])
   // 11. Iterate:
   for (int k = 1; k <= max_it; k++)
   {
-      if (k > 1) { alpha *= ((real_t) k) / ((real_t) k-1); }
+      if (k > 1) { alpha *= ((double) k) / ((double) k-1); }

      if (myid == 0)
      {
@@ -452,16 +450,15 @@ int main(int argc, char *argv[])

      // Step 5 - Update design variable ψ ← proj(ψ - αG)
      psi.Add(-alpha, grad);
-      const real_t material_volume = proj(psi, target_volume);
+      const double material_volume = proj(psi, target_volume);

      // Compute ||ρ - ρ_old|| in control fes.
-      real_t norm_increment = zerogf.ComputeL1Error(succ_diff_rho);
-      real_t norm_reduced_gradient = norm_increment/alpha;
+      double norm_increment = zerogf.ComputeL1Error(succ_diff_rho);
+      double norm_reduced_gradient = norm_increment/alpha;
      psi_old = psi;

-      real_t compliance = (*(ElasticitySolver->GetLinearForm()))(u);
-      MPI_Allreduce(MPI_IN_PLACE, &compliance, 1, MPITypeMap<real_t>::mpi_type,
-                    MPI_SUM, MPI_COMM_WORLD);
+      double compliance = (*(ElasticitySolver->GetLinearForm()))(u);
+      MPI_Allreduce(MPI_IN_PLACE,&compliance,1,MPI_DOUBLE,MPI_SUM,MPI_COMM_WORLD);
      if (myid == 0)
      {
         mfem::out << "norm of the reduced gradient = " << norm_reduced_gradient << endl;
@@ -483,7 +480,7 @@ int main(int argc, char *argv[])
      {
         rho_gf.ProjectCoefficient(rho);
         paraview_dc.SetCycle(k);
-         paraview_dc.SetTime((real_t)k);
+         paraview_dc.SetTime((double)k);
         paraview_dc.Save();
      }

@@ -1,696 +0,0 @@
-//                                MFEM Example 38
-//
-// Compile with: make ex38
-//
-// Sample runs:
-// (since all sample runs require LAPACK, the * symbol is used to exclude them
-// from the automatically generated internal MFEM tests).
-//              * ex38
-//              * ex38 -i volumetric1d
-//              * ex38 -i surface2d
-//              * ex38 -i surface2d -o 4 -r 5
-//              * ex38 -i volumetric2d
-//              * ex38 -i volumetric2d -o 4 -r 5
-//              * ex38 -i surface3d
-//              * ex38 -i surface3d -o 4 -r 5
-//              * ex38 -i volumetric3d
-//              * ex38 -i volumetric3d -o 4 -r 5
-//
-// Description: This example code demonstrates the use of MFEM to integrate
-//              functions over implicit interfaces and subdomains bounded by
-//              implicit interfaces.
-//
-//              The quadrature rules are constructed by means of moment-fitting.
-//              The interface is given by the zero isoline of a level-set
-//              function ϕ and the subdomain is given as the domain where ϕ>0
-//              holds. The algorithm for construction of the quadrature rules
-//              was introduced by Mueller, Kummer and Oberlack [1].
-//
-//              This example also showcases how to set up integrators using the
-//              integration rules on implicit surfaces and subdomains.
-//
-// [1] Mueller, B., Kummer, F. and Oberlack, M. (2013) Highly accurate surface
-//     and volume integration on implicit domains by means of moment-fitting.
-//     Int. J. Numer. Meth. Engr. (96) 512-528. DOI:10.1002/nme.4569
-
-#include "mfem.hpp"
-#include <iostream>
-
-using namespace std;
-using namespace mfem;
-
-/// @brief Integration rule the example should demonstrate
-enum class IntegrationType { Volumetric1D, Surface2D, Volumetric2D,
-                             Surface3D, Volumetric3D
-                           };
-IntegrationType itype;
-
-/// @brief Level-set function defining the implicit interface
-real_t lvlset(const Vector& X)
-{
-   switch (itype)
-   {
-      case IntegrationType::Volumetric1D:
-         return .55 - X(0);
-      case IntegrationType::Surface2D:
-         return 1. - (pow(X(0), 2.) + pow(X(1), 2.));
-      case IntegrationType::Volumetric2D:
-         return 1. - (pow(X(0) / 1.5, 2.) + pow(X(1) / .75, 2.));
-      case IntegrationType::Surface3D:
-         return 1. - (pow(X(0), 2.) + pow(X(1), 2.) + pow(X(2), 2.));
-      case IntegrationType::Volumetric3D:
-         return 1. - (pow(X(0) / 1.5, 2.) + pow(X(1) / .75, 2.) + pow(X(2) / .5, 2.));
-      default:
-         return 1.;
-   }
-}
-
-/// @brief Function that should be integrated
-real_t integrand(const Vector& X)
-{
-   switch (itype)
-   {
-      case IntegrationType::Volumetric1D:
-         return 1.;
-      case IntegrationType::Surface2D:
-         return 3. * pow(X(0), 2.) - pow(X(1), 2.);
-      case IntegrationType::Volumetric2D:
-         return 1.;
-      case IntegrationType::Surface3D:
-         return 4. - 3. * pow(X(0), 2.) + 2. * pow(X(1), 2.) - pow(X(2), 2.);
-      case IntegrationType::Volumetric3D:
-         return 1.;
-      default:
-         return 0.;
-   }
-}
-
-/// @brief Analytic surface integral
-real_t Surface()
-{
-   switch (itype)
-   {
-      case IntegrationType::Volumetric1D:
-         return 1.;
-      case IntegrationType::Surface2D:
-         return 2. * M_PI;
-      case IntegrationType::Volumetric2D:
-         return 7.26633616541076;
-      case IntegrationType::Surface3D:
-         return 40. / 3. * M_PI;
-      case IntegrationType::Volumetric3D:
-         return 9.90182151329315;
-      default:
-         return 0.;
-   }
-}
-
-/// @brief Analytic volume integral over subdomain with positive level-set
-real_t Volume()
-{
-   switch (itype)
-   {
-      case IntegrationType::Volumetric1D:
-         return .55;
-      case IntegrationType::Surface2D:
-         return NAN;
-      case IntegrationType::Volumetric2D:
-         return 9. / 8. * M_PI;
-      case IntegrationType::Surface3D:
-         return NAN;
-      case IntegrationType::Volumetric3D:
-         return 3. / 4. * M_PI;
-      default:
-         return 0.;
-   }
-}
-
-#ifdef MFEM_USE_LAPACK
-/**
- @brief Class for surface IntegrationRule
-
- This class demonstrates how IntegrationRules computed as CutIntegrationRules
- can be saved to reduce the impact by computing them from scratch each time.
- */
-class SIntegrationRule : public IntegrationRule
-{
-protected:
-   /// @brief Space Dimension of the IntegrationRule
-   int dim;
-   /// @brief Column-wise matrix of the quadtrature weights
-   DenseMatrix Weights;
-   /// @brief Column-wise matrix of the transformation weights of the normal
-   DenseMatrix SurfaceWeights;
-
-public:
-   /**
-    @brief Constructor of SIntegrationRule
-
-    The surface integrationRules are computed and saved in the constructor.
-
-    @param [in] Order Order of the IntegrationRule
-    @param [in] LvlSet Level-set defining the implicit interface
-    @param [in] lsOrder Polynomial degree for approx of level-set function
-    @param [in] mesh Pointer to the mesh that is used
-   */
-   SIntegrationRule(int Order, Coefficient& LvlSet, int lsOrder, Mesh* mesh)
-   {
-      dim = mesh->Dimension();
-
-      IsoparametricTransformation Tr;
-      MomentFittingIntRules MFIRs(Order, LvlSet, lsOrder);
-      mesh->GetElementTransformation(0, &Tr);
-      IntegrationRule ir;
-      MFIRs.GetSurfaceIntegrationRule(Tr, ir);
-      if (dim >1)
-      {
-         Weights.SetSize(ir.GetNPoints(), mesh->GetNE());
-      }
-      else
-      {
-         Weights.SetSize(2, mesh->GetNE());
-      }
-      SurfaceWeights.SetSize(ir.GetNPoints(), mesh->GetNE());
-      Vector w;
-      MFIRs.GetSurfaceWeights(Tr, ir, w);
-      SurfaceWeights.SetCol(0, w);
-      SetSize(ir.GetNPoints());
-
-      for (int ip = 0; ip < GetNPoints(); ip++)
-      {
-         IntPoint(ip).index = ip;
-         IntegrationPoint &intp = IntPoint(ip);
-         intp.x = ir.IntPoint(ip).x;
-         intp.y = ir.IntPoint(ip).y;
-         intp.z = ir.IntPoint(ip).z;
-         if (dim > 1)
-         {
-            Weights(ip, 0) = ir.IntPoint(ip).weight;
-         }
-         else
-         {
-            Weights(0, 0) = ir.IntPoint(ip).x;
-            Weights(1, 0) = ir.IntPoint(ip).weight;
-         }
-      }
-
-
-      for (int elem = 1; elem < mesh->GetNE(); elem++)
-      {
-         mesh->GetElementTransformation(elem, &Tr);
-         MFIRs.GetSurfaceIntegrationRule(Tr, ir);
-         Vector w;
-         MFIRs.GetSurfaceWeights(Tr, ir, w);
-         SurfaceWeights.SetCol(elem, w);
-
-         for (int ip = 0; ip < GetNPoints(); ip++)
-         {
-            if (dim > 1)
-            {
-               Weights(ip, elem) = ir.IntPoint(ip).weight;
-            }
-            else
-            {
-               Weights(0, elem) = ir.IntPoint(ip).x;
-               Weights(1, elem) = ir.IntPoint(ip).weight;
-            }
-         }
-      }
-   }
-
-   /**
-    @brief Set the weights for the given element and multiply them with the
-    transformation of the interface
-    */
-   void SetElementinclSurfaceWeight(int Element)
-   {
-      if (dim == 1)
-      {
-         IntegrationPoint &intp = IntPoint(0);
-         intp.x = Weights(0, Element);
-         intp.weight = Weights(1, Element);
-         cout << intp.x << " " << Element << endl;
-      }
-      else
-         for (int ip = 0; ip < GetNPoints(); ip++)
-         {
-            IntegrationPoint &intp = IntPoint(ip);
-            intp.weight = Weights(ip, Element) * SurfaceWeights(ip, Element);
-         }
-   }
-
-   /// @brief Set the weights for the given element
-   void SetElement(int Element)
-   {
-      if (dim == 1)
-      {
-         IntegrationPoint &intp = IntPoint(0);
-         intp.x = Weights(0, Element);
-         intp.weight = Weights(1, Element);
-      }
-      else
-         for (int ip = 0; ip < GetNPoints(); ip++)
-         {
-            IntegrationPoint &intp = IntPoint(ip);
-            intp.weight = Weights(ip, Element);
-         }
-   }
-
-   /// @brief Destructor of SIntegrationRule
-   ~SIntegrationRule() {}
-};
-
-/**
- @brief Class for volume IntegrationRule
-
- This class demonstrates how IntegrationRules computed as CutIntegrationRules
- can be saved to reduce the impact by computing them from scratch each time.
- */
-class CIntegrationRule : public IntegrationRule
-{
-protected:
-   /// @brief Space Dimension of the IntegrationRule
-   int dim;
-   /// @brief Column-wise matrix of the quadtrature weights
-   DenseMatrix Weights;
-
-public:
-   /**
-    @brief Constructor of CIntegrationRule
-
-    The volume integrationRules are computed and saved in the constructor.
-
-    @param [in] Order Order of the IntegrationRule
-    @param [in] LvlSet Level-set defining the implicit interface
-    @param [in] lsOrder Polynomial degree for approx of level-set function
-    @param [in] mesh Pointer to the mesh that is used
-   */
-   CIntegrationRule(int Order, Coefficient& LvlSet, int lsOrder, Mesh* mesh)
-   {
-      dim = mesh->Dimension();
-
-      IsoparametricTransformation Tr;
-      MomentFittingIntRules MFIRs(Order, LvlSet, lsOrder);
-      mesh->GetElementTransformation(0, &Tr);
-      IntegrationRule ir;
-      MFIRs.GetVolumeIntegrationRule(Tr, ir);
-      if (dim > 1)
-      {
-         Weights.SetSize(ir.GetNPoints(), mesh->GetNE());
-      }
-      else
-      {
-         Weights.SetSize(2 * ir.GetNPoints(), mesh->GetNE());
-      }
-
-      SetSize(ir.GetNPoints());
-      for (int ip = 0; ip < GetNPoints(); ip++)
-      {
-         IntPoint(ip).index = ip;
-         IntegrationPoint &intp = IntPoint(ip);
-         intp.x = ir.IntPoint(ip).x;
-         intp.y = ir.IntPoint(ip).y;
-         intp.z = ir.IntPoint(ip).z;
-         if (dim > 1)
-         {
-            Weights(ip, 0) = ir.IntPoint(ip).weight;
-         }
-         else
-         {
-            Weights(2 * ip, 0) = ir.IntPoint(ip).x;
-            Weights(2 * ip + 1, 0) = ir.IntPoint(ip).weight;
-         }
-      }
-
-      for (int elem = 1; elem < mesh->GetNE(); elem++)
-      {
-         mesh->GetElementTransformation(elem, &Tr);
-         MFIRs.GetVolumeIntegrationRule(Tr, ir);
-
-         for (int ip = 0; ip < GetNPoints(); ip++)
-         {
-            if (dim > 1)
-            {
-               Weights(ip, elem) = ir.IntPoint(ip).weight;
-            }
-            else
-            {
-               Weights(2 * ip, elem) = ir.IntPoint(ip).x;
-               Weights(2 * ip + 1, elem) = ir.IntPoint(ip).weight;
-            }
-         }
-      }
-   }
-
-   /// @brief Set the weights for the given element
-   void SetElement(int Element)
-   {
-      if (dim == 1)
-         for (int ip = 0; ip < GetNPoints(); ip++)
-         {
-            IntegrationPoint &intp = IntPoint(ip);
-            intp.x = Weights(2 * ip, Element);
-            intp.weight = Weights(2 * ip + 1, Element);
-         }
-      else
-         for (int ip = 0; ip < GetNPoints(); ip++)
-         {
-            IntegrationPoint &intp = IntPoint(ip);
-            intp.weight = Weights(ip, Element);
-         }
-   }
-
-   /// @brief Destructor of CIntegrationRule
-   ~CIntegrationRule() {}
-};
-/**
- @brief Class for surface linearform integrator
-
- Integrator to demonstrate the use of the surface integration rule on an
- implicit surface defined by a level-set.
- */
-class SurfaceLFIntegrator : public LinearFormIntegrator
-{
-protected:
-   /// @brief vector to evaluate the basis functions
-   Vector shape;
-
-   /// @brief surface integration rule
-   SIntegrationRule* SIntRule;
-
-   /// @brief coefficient representing the level-set defining the interface
-   Coefficient &LevelSet;
-
-   /// @brief coefficient representing the integrand
-   Coefficient &Q;
-
-public:
-   /**
-    @brief Constructor for the surface linear form integrator
-
-    Constructor for the surface linear form integrator to demonstrate the use
-    of the surface integration rule by means of moment-fitting.
-
-    @param [in] q coefficient representing the inegrand
-    @param [in] levelset level-set defining the implicit interfac
-    @param [in] ir surface integrtion rule to be used
-    */
-   SurfaceLFIntegrator(Coefficient &q, Coefficient &levelset,
-                       SIntegrationRule* ir)
-      : LinearFormIntegrator(), SIntRule(ir), LevelSet(levelset), Q(q) { }
-
-   /**
-    @brief Assembly of the element vector
-
-    Assemble the element vector of for the right hand side on the element given
-    by the FiniteElement and ElementTransformation.
-
-    @param [in] el finite Element the vector belongs to
-    @param [in] Tr transformation of finite element
-    @param [out] elvect vector containing the
-   */
-   virtual void AssembleRHSElementVect(const FiniteElement &el,
-                                       ElementTransformation &Tr,
-                                       Vector &elvect) override
-   {
-      int dof = el.GetDof();
-      shape.SetSize(dof);
-      elvect.SetSize(dof);
-      elvect = 0.;
-
-      // Update the surface integration rule for the current element
-      SIntRule->SetElementinclSurfaceWeight(Tr.ElementNo);
-
-      for (int ip = 0; ip < SIntRule->GetNPoints(); ip++)
-      {
-         Tr.SetIntPoint((&(SIntRule->IntPoint(ip))));
-         real_t val = Tr.Weight() * Q.Eval(Tr, SIntRule->IntPoint(ip));
-         el.CalcShape(SIntRule->IntPoint(ip), shape);
-         add(elvect, SIntRule->IntPoint(ip).weight * val, shape, elvect);
-      }
-   }
-};
-
-/**
- @brief Class for subdomain linearform integrator
-
- Integrator to demonstrate the use of the subdomain integration rule within
- an area defined by an implicit surface defined by a level-set.
- */
-class SubdomainLFIntegrator : public LinearFormIntegrator
-{
-protected:
-   /// @brief vector to evaluate the basis functions
-   Vector shape;
-
-   /// @brief surface integration rule
-   CIntegrationRule* CIntRule;
-
-   /// @brief coefficient representing the level-set defining the interface
-   Coefficient &LevelSet;
-
-   /// @brief coefficient representing the integrand
-   Coefficient &Q;
-
-public:
-   /**
-    @brief Constructor for the volumetric subdomain linear form integrator
-
-    Constructor for the subdomain linear form integrator to demonstrate the use
-    of the volumetric subdomain integration rule by means of moment-fitting.
-
-    @param [in] q coefficient representing the inegrand
-    @param [in] levelset level-set defining the implicit interfac
-    @param [in] ir subdomain integrtion rule to be used
-    */
-   SubdomainLFIntegrator(Coefficient &q, Coefficient &levelset,
-                         CIntegrationRule* ir)
-      : LinearFormIntegrator(), CIntRule(ir), LevelSet(levelset), Q(q) { }
-
-   /**
-    @brief Assembly of the element vector
-
-    Assemble the element vector of for the right hand side on the element given
-    by the FiniteElement and ElementTransformation.
-
-    @param [in] el finite Element the vector belongs to
-    @param [in] Tr transformation of finite element
-    @param [out] elvect vector containing the
-   */
-   virtual void AssembleRHSElementVect(const FiniteElement &el,
-                                       ElementTransformation &Tr,
-                                       Vector &elvect) override
-   {
-      int dof = el.GetDof();
-      shape.SetSize(dof);
-      elvect.SetSize(dof);
-      elvect = 0.;
-
-      // Update the subdomain integration rule
-      CIntRule->SetElement(Tr.ElementNo);
-
-      for (int ip = 0; ip < CIntRule->GetNPoints(); ip++)
-      {
-         Tr.SetIntPoint((&(CIntRule->IntPoint(ip))));
-         real_t val = Tr.Weight()
-                      * Q.Eval(Tr, CIntRule->IntPoint(ip));
-         el.CalcPhysShape(Tr, shape);
-         add(elvect, CIntRule->IntPoint(ip).weight * val, shape, elvect);
-      }
-   }
-};
-#endif // MFEM_USE_LAPACK
-
-int main(int argc, char *argv[])
-{
-#ifndef MFEM_USE_LAPACK
-   cout << "MFEM must be built with LAPACK for this example." << endl;
-   return EXIT_FAILURE;
-#else
-   // 1. Parse he command-line options.
-   int ref_levels = 3;
-   int order = 2;
-   const char *inttype = "surface2d";
-   bool visualization = true;
-   itype = IntegrationType::Surface2D;
-
-   OptionsParser args(argc, argv);
-   args.AddOption(&order, "-o", "--order", "Order of quadrature rule");
-   args.AddOption(&ref_levels, "-r", "--refine", "Number of meh refinements");
-   args.AddOption(&inttype, "-i", "--integrationtype",
-                  "IntegrationType to demonstrate");
-   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
-                  "--no-visualization",
-                  "Enable or disable GLVis visualization.");
-   args.ParseCheck();
-
-   if (strcmp(inttype, "volumetric1d") == 0
-       || strcmp(inttype, "Volumetric1D") == 0)
-   {
-      itype = IntegrationType::Volumetric1D;
-   }
-   else if (strcmp(inttype, "surface2d") == 0
-            || strcmp(inttype, "Surface2D") == 0)
-   {
-      itype = IntegrationType::Surface2D;
-   }
-   else if (strcmp(inttype, "volumetric2d") == 0
-            || strcmp(inttype, "Volumetric2D") == 0)
-   {
-      itype = IntegrationType::Volumetric2D;
-   }
-   else if (strcmp(inttype, "surface3d") == 0
-            || strcmp(inttype, "Surface3d") == 0)
-   {
-      itype = IntegrationType::Surface3D;
-   }
-   else if (strcmp(inttype, "volumetric3d") == 0
-            || strcmp(inttype, "Volumetric3d") == 0)
-   {
-      itype = IntegrationType::Volumetric3D;
-   }
-
-   // 2. Construct and refine the mesh.
-   Mesh *mesh;
-   if (itype == IntegrationType::Volumetric1D)
-   {
-      mesh = new Mesh("../data/inline-segment.mesh");
-   }
-   if (itype == IntegrationType::Surface2D
-       || itype == IntegrationType::Volumetric2D)
-   {
-      mesh = new Mesh(2, 4, 1, 0, 2);
-      mesh->AddVertex(-1.6,-1.6);
-      mesh->AddVertex(1.6,-1.6);
-      mesh->AddVertex(1.6,1.6);
-      mesh->AddVertex(-1.6,1.6);
-      mesh->AddQuad(0,1,2,3);
-      mesh->FinalizeQuadMesh(1, 0, 1);
-   }
-   else if (itype == IntegrationType::Surface3D
-            || itype == IntegrationType::Volumetric3D)
-   {
-      mesh = new Mesh(3, 8, 1, 0, 3);
-      mesh->AddVertex(-1.6,-1.6,-1.6);
-      mesh->AddVertex(1.6,-1.6,-1.6);
-      mesh->AddVertex(1.6,1.6,-1.6);
-      mesh->AddVertex(-1.6,1.6,-1.6);
-      mesh->AddVertex(-1.6,-1.6,1.6);
-      mesh->AddVertex(1.6,-1.6,1.6);
-      mesh->AddVertex(1.6,1.6,1.6);
-      mesh->AddVertex(-1.6,1.6,1.6);
-      mesh->AddHex(0,1,2,3,4,5,6,7);
-      mesh->FinalizeHexMesh(1, 0, 1);
-   }
-
-   for (int lev = 0; lev < ref_levels; lev++)
-   {
-      mesh->UniformRefinement();
-   }
-
-   // 3. Define the necessary finite element space on the mesh.
-   H1_FECollection fe_coll(1, mesh->Dimension());
-   FiniteElementSpace *fespace = new FiniteElementSpace(mesh, &fe_coll);
-
-   // 4. Construction Coefficients for the level set and the integrand.
-   FunctionCoefficient levelset(lvlset);
-   FunctionCoefficient u(integrand);
-
-   // 5. Define the necessary Integration rules on element 0.
-   IsoparametricTransformation Tr;
-   mesh->GetElementTransformation(0, &Tr);
-   SIntegrationRule* sir = new SIntegrationRule(order, levelset, 2, mesh);
-   CIntegrationRule* cir = NULL;
-   if (itype == IntegrationType::Volumetric1D
-       || itype == IntegrationType::Volumetric2D
-       || itype == IntegrationType::Volumetric3D)
-   {
-      cir = new CIntegrationRule(order, levelset, 2, mesh);
-   }
-
-   // 6. Define and assemble the linear forms on the finite element space.
-   LinearForm surface(fespace);
-   LinearForm volume(fespace);
-
-   surface.AddDomainIntegrator(new SurfaceLFIntegrator(u, levelset, sir));
-   surface.Assemble();
-
-   if (itype == IntegrationType::Volumetric1D
-       || itype == IntegrationType::Volumetric2D
-       || itype == IntegrationType::Volumetric3D)
-   {
-      volume.AddDomainIntegrator(new SubdomainLFIntegrator(u, levelset, cir));
-      volume.Assemble();
-   }
-
-   // 7. Print information, computed values and errors to the console.
-   int qorder = 0;
-   int nbasis = 2 * (order + 1) + (int)(order * (order + 1) / 2);
-   IntegrationRules irs(0, Quadrature1D::GaussLegendre);
-   IntegrationRule ir = irs.Get(Geometry::SQUARE, qorder);
-   for (; ir.GetNPoints() <= nbasis; qorder++)
-   {
-      ir = irs.Get(Geometry::SQUARE, qorder);
-   }
-   cout << "============================================" << endl;
-   cout << "Mesh size dx:                       ";
-   if (itype != IntegrationType::Volumetric1D)
-   {
-      cout << 3.2 / pow(2., (real_t)ref_levels) << endl;
-   }
-   else
-   {
-      cout << .25 / pow(2., (real_t)ref_levels) << endl;
-   }
-   if (itype == IntegrationType::Surface2D
-       || itype == IntegrationType::Volumetric2D)
-   {
-      cout << "Number of div free basis functions: " << nbasis << endl;
-      cout << "Number of quadrature points:        " << ir.GetNPoints() << endl;
-   }
-   cout << scientific << setprecision(2);
-   cout << "============================================" << endl;
-   cout << "Computed value of surface integral: " << surface.Sum() << endl;
-   cout << "True value of surface integral:     " << Surface() << endl;
-   cout << "Absolute Error (Surface):            ";
-   cout << abs(surface.Sum() - Surface()) << endl;
-   cout << "Relative Error (Surface):           ";
-   cout << abs(surface.Sum() - Surface()) / Surface() << endl;
-   if (itype == IntegrationType::Volumetric1D
-       || itype == IntegrationType::Volumetric2D
-       || itype == IntegrationType::Volumetric3D)
-   {
-      cout << "--------------------------------------------" << endl;
-      cout << "Computed value of volume integral:  " << volume.Sum() << endl;
-      cout << "True value of volume integral:      " << Volume() << endl;
-      cout << "Absolute Error (Volume):             ";
-      cout << abs(volume.Sum() - Volume()) << endl;
-      cout << "Relative Error (Volume):            ";
-      cout << abs(volume.Sum() - Volume()) / Volume() << endl;
-   }
-   cout << "============================================" << endl;
-
-   // 8. Plot the level-set function on a high order finite element space.
-   if (visualization)
-   {
-      H1_FECollection fe_coll2(5, mesh->Dimension());
-      FiniteElementSpace fespace2(mesh, &fe_coll2);
-      FunctionCoefficient levelset_coeff(levelset);
-      GridFunction lgf(&fespace2);
-      lgf.ProjectCoefficient(levelset_coeff);
-      char vishost[] = "localhost";
-      int  visport   = 19916;
-      socketstream sol_sock(vishost, visport);
-      sol_sock.precision(8);
-      sol_sock << "solution\n" << *mesh << lgf << flush;
-      sol_sock << "keys pppppppppppppppppppppppppppcmmlRj\n";
-      sol_sock << "levellines " << 0. << " " << 0. << " " << 1 << "\n" << flush;
-   }
-
-   delete sir;
-   delete cir;
-   delete fespace;
-   delete mesh;
-   return EXIT_SUCCESS;
-#endif //MFEM_USE_LAPACK
-}
@@ -5,7 +5,6 @@
 // Sample runs:  mpirun -np 4 ex3p -m ../data/star.mesh
 //               mpirun -np 4 ex3p -m ../data/square-disc.mesh -o 2
 //               mpirun -np 4 ex3p -m ../data/beam-tet.mesh
-//               mpirun -np 4 ex3p -m ../data/beam-tet.mesh -nc -o 2
 //               mpirun -np 4 ex3p -m ../data/beam-hex.mesh
 //               mpirun -np 4 ex3p -m ../data/beam-hex.mesh -o 2 -pa
 //               mpirun -np 4 ex3p -m ../data/escher.mesh
@@ -55,7 +54,7 @@ using namespace mfem;
 // Exact solution, E, and r.h.s., f. See below for implementation.
 void E_exact(const Vector &, Vector &);
 void f_exact(const Vector &, Vector &);
-real_t freq = 1.0, kappa;
+double freq = 1.0, kappa;
 int dim;

 int main(int argc, char *argv[])
@@ -71,7 +70,6 @@ int main(int argc, char *argv[])
   int order = 1;
   bool static_cond = false;
   bool pa = false;
-   bool nc = false;
   const char *device_config = "cpu";
   bool visualization = true;
 #ifdef MFEM_USE_AMGX
@@ -89,9 +87,6 @@ int main(int argc, char *argv[])
                  "--no-static-condensation", "Enable static condensation.");
   args.AddOption(&pa, "-pa", "--partial-assembly", "-no-pa",
                  "--no-partial-assembly", "Enable Partial Assembly.");
-   args.AddOption(&nc, "-nc", "--non-conforming", "-c",
-                  "--conforming",
-                  "Mark the mesh as nonconforming before partitioning.");
   args.AddOption(&device_config, "-d", "--device",
                  "Device configuration string, see Device::Configure().");
   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
@@ -129,11 +124,6 @@ int main(int argc, char *argv[])
   Mesh *mesh = new Mesh(mesh_file, 1, 1);
   dim = mesh->Dimension();
   int sdim = mesh->SpaceDimension();
-   if (nc)
-   {
-      // Can set to false to use conformal refinement for simplices.
-      mesh->EnsureNCMesh(true);
-   }

   // 5. Refine the serial mesh on all processors to increase the resolution. In
   //    this example we do 'ref_levels' of uniform refinement. We choose
@@ -263,7 +253,7 @@ int main(int argc, char *argv[])

   // 15. Compute and print the L^2 norm of the error.
   {
-      real_t error = x.ComputeL2Error(E);
+      double error = x.ComputeL2Error(E);
      if (myid == 0)
      {
         cout << "\n|| E_h - E ||_{L^2} = " << error << '\n' << endl;
@@ -54,7 +54,7 @@ using namespace mfem;
 // Exact solution, F, and r.h.s., f. See below for implementation.
 void F_exact(const Vector &, Vector &);
 void f_exact(const Vector &, Vector &);
-real_t freq = 1.0, kappa;
+double freq = 1.0, kappa;

 int main(int argc, char *argv[])
 {
@@ -269,9 +269,9 @@ void F_exact(const Vector &p, Vector &F)
 {
   int dim = p.Size();

-   real_t x = p(0);
-   real_t y = p(1);
-   // real_t z = (dim == 3) ? p(2) : 0.0; // Uncomment if F is changed to depend on z
+   double x = p(0);
+   double y = p(1);
+   // double z = (dim == 3) ? p(2) : 0.0; // Uncomment if F is changed to depend on z

   F(0) = cos(kappa*x)*sin(kappa*y);
   F(1) = cos(kappa*y)*sin(kappa*x);
@@ -286,11 +286,11 @@ void f_exact(const Vector &p, Vector &f)
 {
   int dim = p.Size();

-   real_t x = p(0);
-   real_t y = p(1);
-   // real_t z = (dim == 3) ? p(2) : 0.0; // Uncomment if f is changed to depend on z
+   double x = p(0);
+   double y = p(1);
+   // double z = (dim == 3) ? p(2) : 0.0; // Uncomment if f is changed to depend on z

-   real_t temp = 1 + 2*kappa*kappa;
+   double temp = 1 + 2*kappa*kappa;

   f(0) = temp*cos(kappa*x)*sin(kappa*y);
   f(1) = temp*cos(kappa*y)*sin(kappa*x);
@@ -54,7 +54,7 @@ using namespace mfem;
 // Exact solution, F, and r.h.s., f. See below for implementation.
 void F_exact(const Vector &, Vector &);
 void f_exact(const Vector &, Vector &);
-real_t freq = 1.0, kappa;
+double freq = 1.0, kappa;

 int main(int argc, char *argv[])
 {
@@ -255,7 +255,7 @@ int main(int argc, char *argv[])

   // 15. Compute and print the L^2 norm of the error.
   {
-      real_t error = x.ComputeL2Error(F);
+      double error = x.ComputeL2Error(F);
      if (myid == 0)
      {
         cout << "\n|| F_h - F ||_{L^2} = " << error << '\n' << endl;
@@ -311,9 +311,9 @@ void F_exact(const Vector &p, Vector &F)
 {
   int dim = p.Size();

-   real_t x = p(0);
-   real_t y = p(1);
-   // real_t z = (dim == 3) ? p(2) : 0.0; // Uncomment if F is changed to depend on z
+   double x = p(0);
+   double y = p(1);
+   // double z = (dim == 3) ? p(2) : 0.0; // Uncomment if F is changed to depend on z

   F(0) = cos(kappa*x)*sin(kappa*y);
   F(1) = cos(kappa*y)*sin(kappa*x);
@@ -328,11 +328,11 @@ void f_exact(const Vector &p, Vector &f)
 {
   int dim = p.Size();

-   real_t x = p(0);
-   real_t y = p(1);
-   // real_t z = (dim == 3) ? p(2) : 0.0; // Uncomment if f is changed to depend on z
+   double x = p(0);
+   double y = p(1);
+   // double z = (dim == 3) ? p(2) : 0.0; // Uncomment if f is changed to depend on z

-   real_t temp = 1 + 2*kappa*kappa;
+   double temp = 1 + 2*kappa*kappa;

   f(0) = temp*cos(kappa*x)*sin(kappa*y);
   f(1) = temp*cos(kappa*y)*sin(kappa*x);
@@ -45,10 +45,10 @@ using namespace mfem;

 // Define the analytical solution and forcing terms / boundary conditions
 void uFun_ex(const Vector & x, Vector & u);
-real_t pFun_ex(const Vector & x);
+double pFun_ex(const Vector & x);
 void fFun(const Vector & x, Vector & f);
-real_t gFun(const Vector & x);
-real_t f_natural(const Vector & x);
+double gFun(const Vector & x);
+double f_natural(const Vector & x);

 int main(int argc, char *argv[])
 {
@@ -270,8 +270,8 @@ int main(int argc, char *argv[])
   // 11. Solve the linear system with MINRES.
   //     Check the norm of the unpreconditioned residual.
   int maxIter(1000);
-   real_t rtol(1.e-6);
-   real_t atol(1.e-10);
+   double rtol(1.e-6);
+   double atol(1.e-10);

   chrono.Clear();
   chrono.Start();
@@ -313,10 +313,10 @@ int main(int argc, char *argv[])
      irs[i] = &(IntRules.Get(i, order_quad));
   }

-   real_t err_u  = u.ComputeL2Error(ucoeff, irs);
-   real_t norm_u = ComputeLpNorm(2., ucoeff, *mesh, irs);
-   real_t err_p  = p.ComputeL2Error(pcoeff, irs);
-   real_t norm_p = ComputeLpNorm(2., pcoeff, *mesh, irs);
+   double err_u  = u.ComputeL2Error(ucoeff, irs);
+   double norm_u = ComputeLpNorm(2., ucoeff, *mesh, irs);
+   double err_p  = p.ComputeL2Error(pcoeff, irs);
+   double norm_p = ComputeLpNorm(2., pcoeff, *mesh, irs);

   std::cout << "|| u_h - u_ex || / || u_ex || = " << err_u / norm_u << "\n";
   std::cout << "|| p_h - p_ex || / || p_ex || = " << err_p / norm_p << "\n";
@@ -391,9 +391,9 @@ int main(int argc, char *argv[])

 void uFun_ex(const Vector & x, Vector & u)
 {
-   real_t xi(x(0));
-   real_t yi(x(1));
-   real_t zi(0.0);
+   double xi(x(0));
+   double yi(x(1));
+   double zi(0.0);
   if (x.Size() == 3)
   {
      zi = x(2);
@@ -409,11 +409,11 @@ void uFun_ex(const Vector & x, Vector & u)
 }

 // Change if needed
-real_t pFun_ex(const Vector & x)
+double pFun_ex(const Vector & x)
 {
-   real_t xi(x(0));
-   real_t yi(x(1));
-   real_t zi(0.0);
+   double xi(x(0));
+   double yi(x(1));
+   double zi(0.0);

   if (x.Size() == 3)
   {
@@ -428,7 +428,7 @@ void fFun(const Vector & x, Vector & f)
   f = 0.0;
 }

-real_t gFun(const Vector & x)
+double gFun(const Vector & x)
 {
   if (x.Size() == 3)
   {
@@ -440,7 +440,7 @@ real_t gFun(const Vector & x)
   }
 }

-real_t f_natural(const Vector & x)
+double f_natural(const Vector & x)
 {
   return (-pFun_ex(x));
 }
@@ -46,10 +46,10 @@ using namespace mfem;

 // Define the analytical solution and forcing terms / boundary conditions
 void uFun_ex(const Vector & x, Vector & u);
-real_t pFun_ex(const Vector & x);
+double pFun_ex(const Vector & x);
 void fFun(const Vector & x, Vector & f);
-real_t gFun(const Vector & x);
-real_t f_natural(const Vector & x);
+double gFun(const Vector & x);
+double f_natural(const Vector & x);

 int main(int argc, char *argv[])
 {
@@ -326,8 +326,8 @@ int main(int argc, char *argv[])
   // 13. Solve the linear system with MINRES.
   //     Check the norm of the unpreconditioned residual.
   int maxIter(pa ? 1000 : 500);
-   real_t rtol(1.e-6);
-   real_t atol(1.e-10);
+   double rtol(1.e-6);
+   double atol(1.e-10);

   chrono.Clear();
   chrono.Start();
@@ -371,10 +371,10 @@ int main(int argc, char *argv[])
      irs[i] = &(IntRules.Get(i, order_quad));
   }

-   real_t err_u  = u->ComputeL2Error(ucoeff, irs);
-   real_t norm_u = ComputeGlobalLpNorm(2, ucoeff, *pmesh, irs);
-   real_t err_p  = p->ComputeL2Error(pcoeff, irs);
-   real_t norm_p = ComputeGlobalLpNorm(2, pcoeff, *pmesh, irs);
+   double err_u  = u->ComputeL2Error(ucoeff, irs);
+   double norm_u = ComputeGlobalLpNorm(2, ucoeff, *pmesh, irs);
+   double err_p  = p->ComputeL2Error(pcoeff, irs);
+   double norm_p = ComputeGlobalLpNorm(2, pcoeff, *pmesh, irs);

   if (verbose)
   {
@@ -493,9 +493,9 @@ int main(int argc, char *argv[])

 void uFun_ex(const Vector & x, Vector & u)
 {
-   real_t xi(x(0));
-   real_t yi(x(1));
-   real_t zi(0.0);
+   double xi(x(0));
+   double yi(x(1));
+   double zi(0.0);
   if (x.Size() == 3)
   {
      zi = x(2);
@@ -511,11 +511,11 @@ void uFun_ex(const Vector & x, Vector & u)
 }

 // Change if needed
-real_t pFun_ex(const Vector & x)
+double pFun_ex(const Vector & x)
 {
-   real_t xi(x(0));
-   real_t yi(x(1));
-   real_t zi(0.0);
+   double xi(x(0));
+   double yi(x(1));
+   double zi(0.0);

   if (x.Size() == 3)
   {
@@ -530,7 +530,7 @@ void fFun(const Vector & x, Vector & f)
   f = 0.0;
 }

-real_t gFun(const Vector & x)
+double gFun(const Vector & x)
 {
   if (x.Size() == 3)
   {
@@ -542,7 +542,7 @@ real_t gFun(const Vector & x)
   }
 }

-real_t f_natural(const Vector & x)
+double f_natural(const Vector & x)
 {
   return (-pFun_ex(x));
 }
@@ -28,8 +28,8 @@ using namespace std;
 using namespace mfem;

 // Exact solution and r.h.s., see below for implementation.
-real_t analytic_solution(const Vector &x);
-real_t analytic_rhs(const Vector &x);
+double analytic_solution(const Vector &x);
+double analytic_rhs(const Vector &x);
 void SnapNodes(Mesh &mesh);

 int main(int argc, char *argv[])
@@ -81,7 +81,7 @@ int main(int argc, char *argv[])

   if (elem_type == 0) // inscribed octahedron
   {
-      const real_t tri_v[6][3] =
+      const double tri_v[6][3] =
      {
         { 1,  0,  0}, { 0,  1,  0}, {-1,  0,  0},
         { 0, -1,  0}, { 0,  0,  1}, { 0,  0, -1}
@@ -105,7 +105,7 @@ int main(int argc, char *argv[])
   }
   else // inscribed cube
   {
-      const real_t quad_v[8][3] =
+      const double quad_v[8][3] =
      {
         {-1, -1, -1}, {+1, -1, -1}, {+1, +1, -1}, {-1, +1, -1},
         {-1, -1, +1}, {+1, -1, +1}, {+1, +1, +1}, {-1, +1, +1}
@@ -249,15 +249,15 @@ int main(int argc, char *argv[])
   return 0;
 }

-real_t analytic_solution(const Vector &x)
+double analytic_solution(const Vector &x)
 {
-   real_t l2 = x(0)*x(0) + x(1)*x(1) + x(2)*x(2);
+   double l2 = x(0)*x(0) + x(1)*x(1) + x(2)*x(2);
   return x(0)*x(1)/l2;
 }

-real_t analytic_rhs(const Vector &x)
+double analytic_rhs(const Vector &x)
 {
-   real_t l2 = x(0)*x(0) + x(1)*x(1) + x(2)*x(2);
+   double l2 = x(0)*x(0) + x(1)*x(1) + x(2)*x(2);
   return 7*x(0)*x(1)/l2;
 }

@@ -28,8 +28,8 @@ using namespace std;
 using namespace mfem;

 // Exact solution and r.h.s., see below for implementation.
-real_t analytic_solution(const Vector &x);
-real_t analytic_rhs(const Vector &x);
+double analytic_solution(const Vector &x);
+double analytic_rhs(const Vector &x);
 void SnapNodes(Mesh &mesh);

 int main(int argc, char *argv[])
@@ -101,7 +101,7 @@ int main(int argc, char *argv[])

   if (elem_type == 0) // inscribed octahedron
   {
-      const real_t tri_v[6][3] =
+      const double tri_v[6][3] =
      {
         { 1,  0,  0}, { 0,  1,  0}, {-1,  0,  0},
         { 0, -1,  0}, { 0,  0,  1}, { 0,  0, -1}
@@ -125,7 +125,7 @@ int main(int argc, char *argv[])
   }
   else // inscribed cube
   {
-      const real_t quad_v[8][3] =
+      const double quad_v[8][3] =
      {
         {-1, -1, -1}, {+1, -1, -1}, {+1, +1, -1}, {-1, +1, -1},
         {-1, -1, +1}, {+1, -1, +1}, {+1, +1, +1}, {-1, +1, +1}
@@ -281,7 +281,7 @@ int main(int argc, char *argv[])
   delete b;

   // 12. Compute and print the L^2 norm of the error.
-   real_t error = x.ComputeL2Error(sol_coef);
+   double error = x.ComputeL2Error(sol_coef);
   if (myid == 0)
   {
      cout << "\nL2 norm of error: " << error << endl;
@@ -323,15 +323,15 @@ int main(int argc, char *argv[])
   return 0;
 }

-real_t analytic_solution(const Vector &x)
+double analytic_solution(const Vector &x)
 {
-   real_t l2 = x(0)*x(0) + x(1)*x(1) + x(2)*x(2);
+   double l2 = x(0)*x(0) + x(1)*x(1) + x(2)*x(2);
   return x(0)*x(1)/l2;
 }

-real_t analytic_rhs(const Vector &x)
+double analytic_rhs(const Vector &x)
 {
-   real_t l2 = x(0)*x(0) + x(1)*x(1) + x(2)*x(2);
+   double l2 = x(0)*x(0) + x(1)*x(1) + x(2)*x(2);
   return 7*x(0)*x(1)/l2;
 }

@@ -206,7 +206,7 @@ int main(int argc, char *argv[])
   SparseMatrix * Shat = RAP(matBhat, matSinv, matBhat);

 #ifndef MFEM_USE_SUITESPARSE
-   const real_t prec_rtol = 1e-3;
+   const double prec_rtol = 1e-3;
   const int prec_maxit = 200;
   CGSolver *S0inv = new CGSolver;
   S0inv->SetOperator(matS0);
@@ -240,7 +240,7 @@ int main(int argc, char *argv[])
      Vector LSres(s_test);
      B.Mult(x, LSres);
      LSres -= F;
-      real_t res = sqrt(matSinv.InnerProduct(LSres, LSres));
+      double res = sqrt(matSinv.InnerProduct(LSres, LSres));
      cout << "\n|| B0*x0 + Bhat*xhat - F ||_{S^-1} = " << res << endl;
   }

@@ -283,7 +283,7 @@ int main(int argc, char *argv[])
      B.Mult(x, LSres);
      LSres -= *trueF;
      matSinv->Mult(LSres, tmp);
-      real_t res = sqrt(InnerProduct(LSres, tmp));
+      double res = sqrt(InnerProduct(LSres, tmp));
      if (myid == 0)
      {
         cout << "\n|| B0*x0 + Bhat*xhat - F ||_{S^-1} = " << res << endl;
@@ -58,10 +58,10 @@ int problem;
 void velocity_function(const Vector &x, Vector &v);

 // Initial condition
-real_t u0_function(const Vector &x);
+double u0_function(const Vector &x);

 // Inflow boundary condition
-real_t inflow_function(const Vector &x);
+double inflow_function(const Vector &x);

 // Mesh bounding box
 Vector bb_min, bb_max;
@@ -72,7 +72,7 @@ private:
   SparseMatrix &M, &K, A;
   GMRESSolver linear_solver;
   BlockILU prec;
-   real_t dt;
+   double dt;
 public:
   DG_Solver(SparseMatrix &M_, SparseMatrix &K_, const FiniteElementSpace &fes)
      : M(M_),
@@ -89,7 +89,7 @@ public:
      linear_solver.SetPreconditioner(prec);
   }

-   void SetTimeStep(real_t dt_)
+   void SetTimeStep(double dt_)
   {
      if (dt_ != dt)
      {
@@ -135,7 +135,7 @@ public:
   FE_Evolution(BilinearForm &M_, BilinearForm &K_, const Vector &b_);

   virtual void Mult(const Vector &x, Vector &y) const;
-   virtual void ImplicitSolve(const real_t dt, const Vector &x, Vector &k);
+   virtual void ImplicitSolve(const double dt, const Vector &x, Vector &k);

   virtual ~FE_Evolution();
 };
@@ -153,8 +153,8 @@ int main(int argc, char *argv[])
   bool fa = false;
   const char *device_config = "cpu";
   int ode_solver_type = 4;
-   real_t t_final = 10.0;
-   real_t dt = 0.01;
+   double t_final = 10.0;
+   double dt = 0.01;
   bool visualization = true;
   bool visit = false;
   bool paraview = false;
@@ -293,7 +293,7 @@ int main(int argc, char *argv[])
      k.SetAssemblyLevel(AssemblyLevel::FULL);
   }
   m.AddDomainIntegrator(new MassIntegrator);
-   constexpr real_t alpha = -1.0;
+   constexpr double alpha = -1.0;
   k.AddDomainIntegrator(new ConvectionIntegrator(velocity, alpha));
   k.AddInteriorFaceIntegrator(
      new NonconservativeDGTraceIntegrator(velocity, alpha));
@@ -393,14 +393,14 @@ int main(int argc, char *argv[])
   //    iterations, ti, with a time-step dt).
   FE_Evolution adv(m, k, b);

-   real_t t = 0.0;
+   double t = 0.0;
   adv.SetTime(t);
   ode_solver->Init(adv);

   bool done = false;
   for (int ti = 0; !done; )
   {
-      real_t dt_real = min(dt, t_final - t);
+      double dt_real = min(dt, t_final - t);
      ode_solver->Step(u, t, dt_real);
      ti++;

@@ -450,8 +450,7 @@ int main(int argc, char *argv[])

 // Implementation of class FE_Evolution
 FE_Evolution::FE_Evolution(BilinearForm &M_, BilinearForm &K_, const Vector &b_)
-   : TimeDependentOperator(M_.FESpace()->GetTrueVSize()),
-     M(M_), K(K_), b(b_), z(height)
+   : TimeDependentOperator(M_.Height()), M(M_), K(K_), b(b_), z(M_.Height())
 {
   Array<int> ess_tdof_list;
   if (M.GetAssemblyLevel() == AssemblyLevel::LEGACY)
@@ -482,7 +481,7 @@ void FE_Evolution::Mult(const Vector &x, Vector &y) const
   M_solver.Mult(z, y);
 }

-void FE_Evolution::ImplicitSolve(const real_t dt, const Vector &x, Vector &k)
+void FE_Evolution::ImplicitSolve(const double dt, const Vector &x, Vector &k)
 {
   MFEM_VERIFY(dg_solver != NULL,
               "Implicit time integration is not supported with partial assembly");
@@ -507,7 +506,7 @@ void velocity_function(const Vector &x, Vector &v)
   Vector X(dim);
   for (int i = 0; i < dim; i++)
   {
-      real_t center = (bb_min[i] + bb_max[i]) * 0.5;
+      double center = (bb_min[i] + bb_max[i]) * 0.5;
      X(i) = 2 * (x(i) - center) / (bb_max[i] - bb_min[i]);
   }

@@ -529,7 +528,7 @@ void velocity_function(const Vector &x, Vector &v)
      case 2:
      {
         // Clockwise rotation in 2D around the origin
-         const real_t w = M_PI/2;
+         const double w = M_PI/2;
         switch (dim)
         {
            case 1: v(0) = 1.0; break;
@@ -541,8 +540,8 @@ void velocity_function(const Vector &x, Vector &v)
      case 3:
      {
         // Clockwise twisting rotation in 2D around the origin
-         const real_t w = M_PI/2;
-         real_t d = max((X(0)+1.)*(1.-X(0)),0.) * max((X(1)+1.)*(1.-X(1)),0.);
+         const double w = M_PI/2;
+         double d = max((X(0)+1.)*(1.-X(0)),0.) * max((X(1)+1.)*(1.-X(1)),0.);
         d = d*d;
         switch (dim)
         {
@@ -556,7 +555,7 @@ void velocity_function(const Vector &x, Vector &v)
 }

 // Initial condition
-real_t u0_function(const Vector &x)
+double u0_function(const Vector &x)
 {
   int dim = x.Size();

@@ -564,7 +563,7 @@ real_t u0_function(const Vector &x)
   Vector X(dim);
   for (int i = 0; i < dim; i++)
   {
-      real_t center = (bb_min[i] + bb_max[i]) * 0.5;
+      double center = (bb_min[i] + bb_max[i]) * 0.5;
      X(i) = 2 * (x(i) - center) / (bb_max[i] - bb_min[i]);
   }

@@ -580,28 +579,28 @@ real_t u0_function(const Vector &x)
            case 2:
            case 3:
            {
-               real_t rx = 0.45, ry = 0.25, cx = 0., cy = -0.2, w = 10.;
+               double rx = 0.45, ry = 0.25, cx = 0., cy = -0.2, w = 10.;
               if (dim == 3)
               {
-                  const real_t s = (1. + 0.25*cos(2*M_PI*X(2)));
+                  const double s = (1. + 0.25*cos(2*M_PI*X(2)));
                  rx *= s;
                  ry *= s;
               }
-               return ( std::erfc(w*(X(0)-cx-rx))*std::erfc(-w*(X(0)-cx+rx)) *
-                        std::erfc(w*(X(1)-cy-ry))*std::erfc(-w*(X(1)-cy+ry)) )/16;
+               return ( erfc(w*(X(0)-cx-rx))*erfc(-w*(X(0)-cx+rx)) *
+                        erfc(w*(X(1)-cy-ry))*erfc(-w*(X(1)-cy+ry)) )/16;
            }
         }
      }
      case 2:
      {
-         real_t x_ = X(0), y_ = X(1), rho, phi;
-         rho = std::hypot(x_, y_);
+         double x_ = X(0), y_ = X(1), rho, phi;
+         rho = hypot(x_, y_);
         phi = atan2(y_, x_);
         return pow(sin(M_PI*rho),2)*sin(3*phi);
      }
      case 3:
      {
-         const real_t f = M_PI;
+         const double f = M_PI;
         return sin(f*X(0))*sin(f*X(1));
      }
   }
@@ -609,7 +608,7 @@ real_t u0_function(const Vector &x)
 }

 // Inflow boundary condition (zero for the problems considered in this example)
-real_t inflow_function(const Vector &x)
+double inflow_function(const Vector &x)
 {
   switch (problem)
   {
@@ -59,10 +59,10 @@ int problem;
 void velocity_function(const Vector &x, Vector &v);

 // Initial condition
-real_t u0_function(const Vector &x);
+double u0_function(const Vector &x);

 // Inflow boundary condition
-real_t inflow_function(const Vector &x);
+double inflow_function(const Vector &x);

 // Mesh bounding box
 Vector bb_min, bb_max;
@@ -135,7 +135,7 @@ private:
   HypreParMatrix *A;
   GMRESSolver linear_solver;
   Solver *prec;
-   real_t dt;
+   double dt;
 public:
   DG_Solver(HypreParMatrix &M_, HypreParMatrix &K_, const FiniteElementSpace &fes,
             PrecType prec_type)
@@ -169,7 +169,7 @@ public:
      M.GetDiag(M_diag);
   }

-   void SetTimeStep(real_t dt_)
+   void SetTimeStep(double dt_)
   {
      if (dt_ != dt)
      {
@@ -224,7 +224,7 @@ public:
                PrecType prec_type);

   virtual void Mult(const Vector &x, Vector &y) const;
-   virtual void ImplicitSolve(const real_t dt, const Vector &x, Vector &k);
+   virtual void ImplicitSolve(const double dt, const Vector &x, Vector &k);

   virtual ~FE_Evolution();
 };
@@ -249,8 +249,8 @@ int main(int argc, char *argv[])
   bool fa = false;
   const char *device_config = "cpu";
   int ode_solver_type = 4;
-   real_t t_final = 10.0;
-   real_t dt = 0.01;
+   double t_final = 10.0;
+   double dt = 0.01;
   bool visualization = true;
   bool visit = false;
   bool paraview = false;
@@ -425,7 +425,7 @@ int main(int argc, char *argv[])
   }

   m->AddDomainIntegrator(new MassIntegrator);
-   constexpr real_t alpha = -1.0;
+   constexpr double alpha = -1.0;
   k->AddDomainIntegrator(new ConvectionIntegrator(velocity, alpha));
   k->AddInteriorFaceIntegrator(
      new NonconservativeDGTraceIntegrator(velocity, alpha));
@@ -566,14 +566,14 @@ int main(int argc, char *argv[])
   //     iterations, ti, with a time-step dt).
   FE_Evolution adv(*m, *k, *B, prec_type);

-   real_t t = 0.0;
+   double t = 0.0;
   adv.SetTime(t);
   ode_solver->Init(adv);

   bool done = false;
   for (int ti = 0; !done; )
   {
-      real_t dt_real = min(dt, t_final - t);
+      double dt_real = min(dt, t_final - t);
      ode_solver->Step(*U, t, dt_real);
      ti++;

@@ -659,9 +659,9 @@ int main(int argc, char *argv[])
 // Implementation of class FE_Evolution
 FE_Evolution::FE_Evolution(ParBilinearForm &M_, ParBilinearForm &K_,
                           const Vector &b_, PrecType prec_type)
-   : TimeDependentOperator(M_.ParFESpace()->GetTrueVSize()), b(b_),
+   : TimeDependentOperator(M_.Height()), b(b_),
     M_solver(M_.ParFESpace()->GetComm()),
-     z(height)
+     z(M_.Height())
 {
   if (M_.GetAssemblyLevel()==AssemblyLevel::LEGACY)
   {
@@ -704,7 +704,7 @@ FE_Evolution::FE_Evolution(ParBilinearForm &M_, ParBilinearForm &K_,
 //    u_t = M^{-1}(Ku + b),
 // by solving associated linear system
 //    (M - dt*K) d = K*u + b
-void FE_Evolution::ImplicitSolve(const real_t dt, const Vector &x, Vector &k)
+void FE_Evolution::ImplicitSolve(const double dt, const Vector &x, Vector &k)
 {
   K->Mult(x, z);
   z += b;
@@ -736,7 +736,7 @@ void velocity_function(const Vector &x, Vector &v)
   Vector X(dim);
   for (int i = 0; i < dim; i++)
   {
-      real_t center = (bb_min[i] + bb_max[i]) * 0.5;
+      double center = (bb_min[i] + bb_max[i]) * 0.5;
      X(i) = 2 * (x(i) - center) / (bb_max[i] - bb_min[i]);
   }

@@ -758,7 +758,7 @@ void velocity_function(const Vector &x, Vector &v)
      case 2:
      {
         // Clockwise rotation in 2D around the origin
-         const real_t w = M_PI/2;
+         const double w = M_PI/2;
         switch (dim)
         {
            case 1: v(0) = 1.0; break;
@@ -770,8 +770,8 @@ void velocity_function(const Vector &x, Vector &v)
      case 3:
      {
         // Clockwise twisting rotation in 2D around the origin
-         const real_t w = M_PI/2;
-         real_t d = max((X(0)+1.)*(1.-X(0)),0.) * max((X(1)+1.)*(1.-X(1)),0.);
+         const double w = M_PI/2;
+         double d = max((X(0)+1.)*(1.-X(0)),0.) * max((X(1)+1.)*(1.-X(1)),0.);
         d = d*d;
         switch (dim)
         {
@@ -785,7 +785,7 @@ void velocity_function(const Vector &x, Vector &v)
 }

 // Initial condition
-real_t u0_function(const Vector &x)
+double u0_function(const Vector &x)
 {
   int dim = x.Size();

@@ -793,7 +793,7 @@ real_t u0_function(const Vector &x)
   Vector X(dim);
   for (int i = 0; i < dim; i++)
   {
-      real_t center = (bb_min[i] + bb_max[i]) * 0.5;
+      double center = (bb_min[i] + bb_max[i]) * 0.5;
      X(i) = 2 * (x(i) - center) / (bb_max[i] - bb_min[i]);
   }

@@ -809,28 +809,28 @@ real_t u0_function(const Vector &x)
            case 2:
            case 3:
            {
-               real_t rx = 0.45, ry = 0.25, cx = 0., cy = -0.2, w = 10.;
+               double rx = 0.45, ry = 0.25, cx = 0., cy = -0.2, w = 10.;
               if (dim == 3)
               {
-                  const real_t s = (1. + 0.25*cos(2*M_PI*X(2)));
+                  const double s = (1. + 0.25*cos(2*M_PI*X(2)));
                  rx *= s;
                  ry *= s;
               }
-               return ( std::erfc(w*(X(0)-cx-rx))*std::erfc(-w*(X(0)-cx+rx)) *
-                        std::erfc(w*(X(1)-cy-ry))*std::erfc(-w*(X(1)-cy+ry)) )/16;
+               return ( erfc(w*(X(0)-cx-rx))*erfc(-w*(X(0)-cx+rx)) *
+                        erfc(w*(X(1)-cy-ry))*erfc(-w*(X(1)-cy+ry)) )/16;
            }
         }
      }
      case 2:
      {
-         real_t x_ = X(0), y_ = X(1), rho, phi;
-         rho = std::hypot(x_, y_);
+         double x_ = X(0), y_ = X(1), rho, phi;
+         rho = hypot(x_, y_);
         phi = atan2(y_, x_);
         return pow(sin(M_PI*rho),2)*sin(3*phi);
      }
      case 3:
      {
-         const real_t f = M_PI;
+         const double f = M_PI;
         return sin(f*X(0))*sin(f*X(1));
      }
   }
@@ -838,7 +838,7 @@ real_t u0_function(const Vector &x)
 }

 // Inflow boundary condition (zero for the problems considered in this example)
-real_t inflow_function(const Vector &x)
+double inflow_function(const Vector &x)
 {
   switch (problem)
   {
@@ -3,28 +3,28 @@
 //
 // Compile with: make ex1
 //
-// Sample runs:  ex1 -m ../../data/square-disc.mesh
-//               ex1 -m ../../data/star.mesh
-//               ex1 -m ../../data/star-mixed.mesh
-//               ex1 -m ../../data/escher.mesh
-//               ex1 -m ../../data/fichera.mesh
-//               ex1 -m ../../data/fichera-mixed.mesh
-//               ex1 -m ../../data/toroid-wedge.mesh
-//               ex1 -m ../../data/square-disc-p2.vtk -o 2
-//               ex1 -m ../../data/square-disc-p3.mesh -o 3
-//               ex1 -m ../../data/square-disc-nurbs.mesh -o -1
-//               ex1 -m ../../data/star-mixed-p2.mesh -o 2
-//               ex1 -m ../../data/disc-nurbs.mesh -o -1
-//               ex1 -m ../../data/pipe-nurbs.mesh -o -1
-//               ex1 -m ../../data/fichera-mixed-p2.mesh -o 2
-//               ex1 -m ../../data/star-surf.mesh
-//               ex1 -m ../../data/square-disc-surf.mesh
-//               ex1 -m ../../data/inline-segment.mesh
-//               ex1 -m ../../data/amr-quad.mesh
-//               ex1 -m ../../data/amr-hex.mesh
-//               ex1 -m ../../data/fichera-amr.mesh
-//               ex1 -m ../../data/mobius-strip.mesh
-//               ex1 -m ../../data/mobius-strip.mesh -o -1 -sc
+// Sample runs:  ex1 -m ../data/square-disc.mesh
+//               ex1 -m ../data/star.mesh
+//               ex1 -m ../data/star-mixed.mesh
+//               ex1 -m ../data/escher.mesh
+//               ex1 -m ../data/fichera.mesh
+//               ex1 -m ../data/fichera-mixed.mesh
+//               ex1 -m ../data/toroid-wedge.mesh
+//               ex1 -m ../data/square-disc-p2.vtk -o 2
+//               ex1 -m ../data/square-disc-p3.mesh -o 3
+//               ex1 -m ../data/square-disc-nurbs.mesh -o -1
+//               ex1 -m ../data/star-mixed-p2.mesh -o 2
+//               ex1 -m ../data/disc-nurbs.mesh -o -1
+//               ex1 -m ../data/pipe-nurbs.mesh -o -1
+//               ex1 -m ../data/fichera-mixed-p2.mesh -o 2
+//               ex1 -m ../data/star-surf.mesh
+//               ex1 -m ../data/square-disc-surf.mesh
+//               ex1 -m ../data/inline-segment.mesh
+//               ex1 -m ../data/amr-quad.mesh
+//               ex1 -m ../data/amr-hex.mesh
+//               ex1 -m ../data/fichera-amr.mesh
+//               ex1 -m ../data/mobius-strip.mesh
+//               ex1 -m ../data/mobius-strip.mesh -o -1 -sc
 //
 // Device sample runs:
 //               ex1 -pa -d cuda
@@ -32,7 +32,7 @@
 //               ex1 -pa -d occa-cuda
 //               ex1 -pa -d raja-omp
 //               ex1 -pa -d occa-omp
-//               ex1 -m ../../data/beam-hex.mesh -pa -d cuda
+//               ex1 -m ../data/beam-hex.mesh -pa -d cuda
 //
 // Description:  This example code demonstrates the use of MFEM to define a
 //               simple finite element discretization of the Laplace problem
@@ -22,19 +22,15 @@ MFEM_LIB_FILE = mfem_is_not_built
 -include $(CONFIG_MK)

 SEQ_EXAMPLES = ex0 ex1 ex2 ex3 ex4 ex5 ex6 ex7 ex8 ex9 ex10 ex14 ex15 ex16 \
-   ex17 ex18 ex19 ex20 ex21 ex22 ex23 ex24 ex25 ex26 ex27 ex28 ex29 ex30 \
-   ex31 ex33 ex34 ex36 ex37
+  ex17 ex18 ex19 ex20 ex21 ex22 ex23 ex24 ex25 ex26 ex27 ex28 ex29 ex30 \
+  ex31 ex33 ex34 ex36 ex37
 PAR_EXAMPLES = ex0p ex1p ex2p ex3p ex4p ex5p ex6p ex7p ex8p ex9p ex10p ex11p \
-   ex12p ex13p ex14p ex15p ex16p ex17p ex18p ex19p ex20p ex21p ex22p ex24p \
-   ex25p ex26p ex27p ex28p ex29p ex30p ex31p ex32p ex33p ex34p ex35p ex36p \
-   ex37p
+  ex12p ex13p ex14p ex15p ex16p ex17p ex18p ex19p ex20p ex21p ex22p ex24p \
+  ex25p ex26p ex27p ex28p ex29p ex30p ex31p ex32p ex33p ex34p ex35p ex36p \
+	ex37p
 SEQ_DEVICE_EXAMPLES = ex1 ex3 ex4 ex5 ex6 ex9 ex22 ex24 ex25 ex26 ex34
 PAR_DEVICE_EXAMPLES = ex1p ex2p ex3p ex4p ex5p ex6p ex7p ex9p ex13p ex22p \
-   ex24p ex25p ex26p ex34p ex35p
-
-ifeq ($(MFEM_USE_LAPACK),YES)
-   SEQ_EXAMPLES += ex38
-endif
+  ex24p ex25p ex26p ex34p ex35p

 ifeq ($(MFEM_USE_MPI),NO)
   EXAMPLES = $(SEQ_EXAMPLES)
@@ -273,13 +273,12 @@ int main(int argc, char *argv[])
 #ifdef MFEM_USE_STRUMPACK
         if (sp_solver)
         {
-            STRUMPACKSolver * strumpack = new STRUMPACKSolver(MPI_COMM_WORLD, argc, argv);
+            STRUMPACKSolver * strumpack = new STRUMPACKSolver(argc, argv, MPI_COMM_WORLD);
            strumpack->SetPrintFactorStatistics(true);
            strumpack->SetPrintSolveStatistics(false);
            strumpack->SetKrylovSolver(strumpack::KrylovSolver::DIRECT);
            strumpack->SetReorderingStrategy(strumpack::ReorderingStrategy::METIS);
-            strumpack->SetMatching(strumpack::MatchingJob::NONE);
-            strumpack->SetCompression(strumpack::CompressionType::NONE);
+            strumpack->DisableMatching();
            strumpack->SetOperator(*Arow);
            strumpack->SetFromCommandLine();
            precond = strumpack;
@@ -17,7 +17,7 @@
 //               finite elements (velocity u) and piecewise discontinuous
 //               polynomials (pressure p).
 //
-//               The example demonstrates the use of the BlockOperator class, as
+//               The example demonstrates the use of the BlockMatrix class, as
 //               well as the collective saving of several grid functions in a
 //               VisIt (visit.llnl.gov) visualization format.
 //
@@ -520,10 +520,10 @@ int main(int argc, char *argv[])
 // Implementation of class FE_Evolution
 FE_Evolution::FE_Evolution(ParBilinearForm &M_, ParBilinearForm &K_,
                           const Vector &b_,bool M_in_lhs)
-   : TimeDependentOperator(M_.ParFESpace()->GetTrueVSize(), 0.0,
+   : TimeDependentOperator(M_.Height(), 0.0,
                           M_in_lhs ? TimeDependentOperator::IMPLICIT
                           : TimeDependentOperator::EXPLICIT),
-     b(b_), comm(M_.ParFESpace()->GetComm()), M_solver(comm), z(height),
+     b(b_), comm(M_.ParFESpace()->GetComm()), M_solver(comm), z(M_.Height()),
     iJacobian(NULL), rJacobian(NULL)
 {
   MAlev = M_.GetAssemblyLevel();
@@ -476,8 +476,7 @@ int main(int argc, char *argv[])

 // Implementation of class FE_Evolution
 FE_Evolution::FE_Evolution(BilinearForm &M_, BilinearForm &K_, const Vector &b_)
-   : TimeDependentOperator(M_.FESpace()->GetTrueVSize()),
-     M(M_), K(K_), b(b_), z(height)
+   : TimeDependentOperator(M_.Height()), M(M_), K(K_), b(b_), z(M_.Height())
 {
   Array<int> ess_tdof_list;
   if (M.GetAssemblyLevel() == AssemblyLevel::LEGACY)
@@ -679,10 +679,10 @@ int main(int argc, char *argv[])
 // Implementation of class FE_Evolution
 FE_Evolution::FE_Evolution(ParBilinearForm &M_, ParBilinearForm &K_,
                           const Vector &b_, PrecType prec_type)
-   : TimeDependentOperator(M_.ParFESpace()->GetTrueVSize()),
+   : TimeDependentOperator(M_.Height()),
     b(b_),
     M_solver(M_.ParFESpace()->GetComm()),
-     z(height)
+     z(M_.Height())
 {
   if (M_.GetAssemblyLevel()==AssemblyLevel::LEGACY)
   {
@@ -25,8 +25,6 @@ set(SRCS
  integ/bilininteg_diffusion_ea.cpp
  integ/bilininteg_diffusion_patch.cpp
  integ/bilininteg_divdiv_pa.cpp
-  integ/bilininteg_elasticity_ea.cpp
-  integ/bilininteg_elasticity_pa.cpp
  integ/bilininteg_gradient_pa.cpp
  integ/bilininteg_interp_pa.cpp
  integ/bilininteg_mass_mf.cpp
@@ -43,7 +41,6 @@ set(SRCS
  integ/bilininteg_vectorfediv_pa.cpp
  integ/bilininteg_vectorfemass_pa.cpp
  integ/bilininteg_diffusion_kernels.cpp
-  integ/bilininteg_elasticity_kernels.cpp
  integ/bilininteg_hcurl_kernels.cpp
  integ/bilininteg_hdiv_kernels.cpp
  integ/bilininteg_hcurlhdiv_kernels.cpp
@@ -80,7 +77,6 @@ set(SRCS
  gridfunc.cpp
  hybridization.cpp
  intrules.cpp
-  intrules_cut.cpp
  ceed/interface/basis.cpp
  ceed/interface/restriction.cpp
  ceed/interface/operator.cpp
@@ -100,6 +96,9 @@ set(SRCS
  lor/lor_ads.cpp
  lor/lor_ams.cpp
  lor/lor_batched.cpp
+  lor/lor_h1.cpp
+  lor/lor_nd.cpp
+  lor/lor_rt.cpp
  multigrid.cpp
  nonlinearform.cpp
  nonlinearform_ext.cpp
@@ -156,7 +155,6 @@ set(HDRS
  bilinearform_ext.hpp
  bilininteg.hpp
  integ/bilininteg_diffusion_kernels.hpp
-  integ/bilininteg_elasticity_kernels.hpp
  integ/bilininteg_hcurl_kernels.hpp
  integ/bilininteg_hdiv_kernels.hpp
  integ/bilininteg_hcurlhdiv_kernels.hpp
@@ -188,7 +186,6 @@ set(HDRS
  gridfunc.hpp
  hybridization.hpp
  intrules.hpp
-  intrules_cut.hpp
  ceed/interface/basis.hpp
  ceed/interface/integrator.hpp
  ceed/interface/interface.hpp
@@ -56,7 +56,7 @@ void BilinearForm::AllocMat()

   int *I = dof_dof.GetI();
   int *J = dof_dof.GetJ();
-   real_t *data = Memory<real_t>(I[height]);
+   double *data = Memory<double>(I[height]);

   mat = new SparseMatrix(I, J, data, height, height, true, true, true);
   *mat = 0.0;
@@ -101,7 +101,6 @@ BilinearForm::BilinearForm (FiniteElementSpace * f, BilinearForm * bf, int ps)

   // Copy the pointers to the integrators
   domain_integs = bf->domain_integs;
-   domain_integs_marker = bf->domain_integs_marker;

   boundary_integs = bf->boundary_integs;
   boundary_integs_marker = bf->boundary_integs_marker;
@@ -209,12 +208,12 @@ void BilinearForm::UseSparsity(SparseMatrix &A)
   UseSparsity(A.GetI(), A.GetJ(), A.ColumnsAreSorted());
 }

-real_t& BilinearForm::Elem (int i, int j)
+double& BilinearForm::Elem (int i, int j)
 {
   return mat -> Elem(i,j);
 }

-const real_t& BilinearForm::Elem (int i, int j) const
+const double& BilinearForm::Elem (int i, int j) const
 {
   return mat -> Elem(i,j);
 }
@@ -434,9 +433,6 @@ void BilinearForm::Assemble(int skip_zeros)
      // Element-wise integration
      for (int i = 0; i < fes -> GetNE(); i++)
      {
-         // Set both doftrans (potentially needed to assemble the element
-         // matrix) and vdofs, which is also needed when the element matrices
-         // are pre-assembled.
         doftrans = fes->GetElementVDofs(i, vdofs);
         if (element_matrices)
         {
@@ -445,8 +441,6 @@ void BilinearForm::Assemble(int skip_zeros)
         else
         {
            const int elem_attr = fes->GetMesh()->GetAttribute(i);
-            eltrans = fes->GetElementTransformation(i);
-
            elmat.SetSize(0);
            for (int k = 0; k < domain_integs.Size(); k++)
            {
@@ -454,8 +448,9 @@ void BilinearForm::Assemble(int skip_zeros)
                    (*(domain_integs_marker[k]))[elem_attr-1] == 1)
                   && !domain_integs[k]->Patchwise())
               {
-                  domain_integs[k]->AssembleElementMatrix(*fes->GetFE(i),
-                                                          *eltrans, elemmat);
+                  const FiniteElement &fe = *fes->GetFE(i);
+                  eltrans = fes->GetElementTransformation(i);
+                  domain_integs[k]->AssembleElementMatrix(fe, *eltrans, elemmat);
                  if (elmat.Size() == 0)
                  {
                     elmat = elemmat;
@@ -1001,7 +996,7 @@ void BilinearForm::EliminateEssentialBC(const Array<int> &bdr_attr_is_ess,
 }

 void BilinearForm::EliminateEssentialBCDiag (const Array<int> &bdr_attr_is_ess,
-                                             real_t value)
+                                             double value)
 {
   Array<int> ess_dofs, conf_ess_dofs;
   fes->GetEssentialVDofs(bdr_attr_is_ess, ess_dofs);
@@ -1077,8 +1072,7 @@ void BilinearForm::EliminateEssentialBCFromDofs(
 void BilinearForm::EliminateEssentialBCFromDofs (const Array<int> &ess_dofs,
                                                 DiagonalPolicy dpolicy)
 {
-   MFEM_ASSERT(ess_dofs.Size() == height,
-               "incorrect dof Array size: " << ess_dofs.Size() << ' ' << height);
+   MFEM_ASSERT(ess_dofs.Size() == height, "incorrect dof Array size");

   for (int i = 0; i < ess_dofs.Size(); i++)
      if (ess_dofs[i] < 0)
@@ -1088,10 +1082,9 @@ void BilinearForm::EliminateEssentialBCFromDofs (const Array<int> &ess_dofs,
 }

 void BilinearForm::EliminateEssentialBCFromDofsDiag (const Array<int> &ess_dofs,
-                                                     real_t value)
+                                                     double value)
 {
-   MFEM_ASSERT(ess_dofs.Size() == height,
-               "incorrect dof Array size: " << ess_dofs.Size() << ' ' << height);
+   MFEM_ASSERT(ess_dofs.Size() == height, "incorrect dof Array size");

   for (int i = 0; i < ess_dofs.Size(); i++)
      if (ess_dofs[i] < 0)
@@ -1229,14 +1222,11 @@ MixedBilinearForm::MixedBilinearForm (FiniteElementSpace *tr_fes,

   // Copy the pointers to the integrators
   domain_integs = mbf->domain_integs;
-   domain_integs_marker = mbf->domain_integs_marker;
-
   boundary_integs = mbf->boundary_integs;
-   boundary_integs_marker = mbf->boundary_integs_marker;
-
   trace_face_integs = mbf->trace_face_integs;
-
   boundary_trace_face_integs = mbf->boundary_trace_face_integs;
+
+   boundary_integs_marker = mbf->boundary_integs_marker;
   boundary_trace_face_integs_marker = mbf->boundary_trace_face_integs_marker;

   assembly = AssemblyLevel::LEGACY;
@@ -1274,12 +1264,12 @@ void MixedBilinearForm::SetAssemblyLevel(AssemblyLevel assembly_level)
   }
 }

-real_t & MixedBilinearForm::Elem (int i, int j)
+double & MixedBilinearForm::Elem (int i, int j)
 {
   return (*mat)(i, j);
 }

-const real_t & MixedBilinearForm::Elem (int i, int j) const
+const double & MixedBilinearForm::Elem (int i, int j) const
 {
   return (*mat)(i, j);
 }
@@ -1291,7 +1281,7 @@ void MixedBilinearForm::Mult(const Vector & x, Vector & y) const
 }

 void MixedBilinearForm::AddMult(const Vector & x, Vector & y,
-                                const real_t a) const
+                                const double a) const
 {
   if (ext)
   {
@@ -1310,7 +1300,7 @@ void MixedBilinearForm::MultTranspose(const Vector & x, Vector & y) const
 }

 void MixedBilinearForm::AddMultTranspose(const Vector & x, Vector & y,
-                                         const real_t a) const
+                                         const double a) const
 {
   if (ext)
   {
@@ -1359,14 +1349,6 @@ void MixedBilinearForm::GetBlocks(Array2D<SparseMatrix *> &blocks) const
 void MixedBilinearForm::AddDomainIntegrator (BilinearFormIntegrator * bfi)
 {
   domain_integs.Append (bfi);
-   domain_integs_marker.Append(NULL); // NULL marker means apply everywhere
-}
-
-void MixedBilinearForm::AddDomainIntegrator (BilinearFormIntegrator * bfi,
-                                             Array<int> &elem_marker)
-{
-   domain_integs.Append (bfi);
-   domain_integs_marker.Append(&elem_marker);
 }

 void MixedBilinearForm::AddBoundaryIntegrator (BilinearFormIntegrator * bfi)
@@ -1401,7 +1383,7 @@ void MixedBilinearForm::AddBdrTraceFaceIntegrator(BilinearFormIntegrator *bfi,
   boundary_trace_face_integs_marker.Append(&bdr_marker);
 }

-void MixedBilinearForm::Assemble(int skip_zeros)
+void MixedBilinearForm::Assemble (int skip_zeros)
 {
   if (ext)
   {
@@ -1423,20 +1405,8 @@ void MixedBilinearForm::Assemble(int skip_zeros)

   if (domain_integs.Size())
   {
-      for (int k = 0; k < domain_integs.Size(); k++)
-      {
-         if (domain_integs_marker[k] != NULL)
-         {
-            MFEM_VERIFY(domain_integs_marker[k]->Size() ==
-                        (mesh->attributes.Size() ? mesh->attributes.Max() : 0),
-                        "invalid element marker for domain integrator #"
-                        << k << ", counting from zero");
-         }
-      }
-
      for (int i = 0; i < test_fes -> GetNE(); i++)
      {
-         const int elem_attr = mesh->GetAttribute(i);
         dom_dof_trans = trial_fes -> GetElementVDofs (i, trial_vdofs);
         ran_dof_trans = test_fes  -> GetElementVDofs (i, test_vdofs);
         eltrans = test_fes -> GetElementTransformation (i);
@@ -1445,14 +1415,10 @@ void MixedBilinearForm::Assemble(int skip_zeros)
         elmat = 0.0;
         for (int k = 0; k < domain_integs.Size(); k++)
         {
-            if (domain_integs_marker[k] == NULL ||
-                (*(domain_integs_marker[k]))[elem_attr-1] == 1)
-            {
-               domain_integs[k] -> AssembleElementMatrix2 (*trial_fes -> GetFE(i),
-                                                           *test_fes  -> GetFE(i),
-                                                           *eltrans, elemmat);
-               elmat += elemmat;
-            }
+            domain_integs[k] -> AssembleElementMatrix2 (*trial_fes -> GetFE(i),
+                                                        *test_fes  -> GetFE(i),
+                                                        *eltrans, elemmat);
+            elmat += elemmat;
         }
         if (ran_dof_trans || dom_dof_trans)
         {
@@ -1975,56 +1941,41 @@ void DiscreteLinearOperator::Assemble(int skip_zeros)
      return;
   }

-   ElementTransformation *eltrans;
+   Array<int> dom_vdofs, ran_vdofs;
+   ElementTransformation *T;
   DofTransformation * dom_dof_trans;
   DofTransformation * ran_dof_trans;
-   DenseMatrix elmat;
-
-   Mesh *mesh = test_fes->GetMesh();
+   const FiniteElement *dom_fe, *ran_fe;
+   DenseMatrix totelmat, elmat;

   if (mat == NULL)
   {
      mat = new SparseMatrix(height, width);
   }

-   if (domain_integs.Size())
+   if (domain_integs.Size() > 0)
   {
-      for (int k = 0; k < domain_integs.Size(); k++)
-      {
-         if (domain_integs_marker[k] != NULL)
-         {
-            MFEM_VERIFY(domain_integs_marker[k]->Size() ==
-                        (mesh->attributes.Size() ? mesh->attributes.Max() : 0),
-                        "invalid element marker for domain integrator #"
-                        << k << ", counting from zero");
-         }
-      }
-
      for (int i = 0; i < test_fes->GetNE(); i++)
      {
-         const int elem_attr = mesh->GetAttribute(i);
-         dom_dof_trans = trial_fes->GetElementVDofs(i, trial_vdofs);
-         ran_dof_trans = test_fes->GetElementVDofs(i, test_vdofs);
-         eltrans = test_fes->GetElementTransformation(i);
+         dom_dof_trans = trial_fes->GetElementVDofs(i, dom_vdofs);
+         ran_dof_trans = test_fes->GetElementVDofs(i, ran_vdofs);
+         T = test_fes->GetElementTransformation(i);
+         dom_fe = trial_fes->GetFE(i);
+         ran_fe = test_fes->GetFE(i);

-         elmat.SetSize(test_vdofs.Size(), trial_vdofs.Size());
-         elmat = 0.0;
-         for (int k = 0; k < domain_integs.Size(); k++)
+         domain_integs[0]->AssembleElementMatrix2(*dom_fe, *ran_fe, *T,
+                                                  totelmat);
+         for (int j = 1; j < domain_integs.Size(); j++)
         {
-            if (domain_integs_marker[k] == NULL ||
-                (*(domain_integs_marker[k]))[elem_attr-1] == 1)
-            {
-               domain_integs[k]->AssembleElementMatrix2(*trial_fes->GetFE(i),
-                                                        *test_fes->GetFE(i),
-                                                        *eltrans, elemmat);
-               elmat += elemmat;
-            }
+            domain_integs[j]->AssembleElementMatrix2(*dom_fe, *ran_fe, *T,
+                                                     elmat);
+            totelmat += elmat;
         }
         if (ran_dof_trans || dom_dof_trans)
         {
-            TransformPrimal(ran_dof_trans, dom_dof_trans, elemmat);
+            TransformPrimal(ran_dof_trans, dom_dof_trans, totelmat);
         }
-         mat->SetSubMatrix(test_vdofs, trial_vdofs, elemmat, skip_zeros);
+         mat->SetSubMatrix(ran_vdofs, dom_vdofs, totelmat, skip_zeros);
      }
   }

@@ -2033,20 +1984,21 @@ void DiscreteLinearOperator::Assemble(int skip_zeros)
      const int nfaces = test_fes->GetMesh()->GetNumFaces();
      for (int i = 0; i < nfaces; i++)
      {
-         trial_fes->GetFaceVDofs(i, trial_vdofs);
-         test_fes->GetFaceVDofs(i, test_vdofs);
-         eltrans = test_fes->GetMesh()->GetFaceTransformation(i);
+         trial_fes->GetFaceVDofs(i, dom_vdofs);
+         test_fes->GetFaceVDofs(i, ran_vdofs);
+         T = test_fes->GetMesh()->GetFaceTransformation(i);
+         dom_fe = trial_fes->GetFaceElement(i);
+         ran_fe = test_fes->GetFaceElement(i);

-         elmat.SetSize(test_vdofs.Size(), trial_vdofs.Size());
-         elmat = 0.0;
-         for (int k = 0; k < trace_face_integs.Size(); k++)
+         trace_face_integs[0]->AssembleElementMatrix2(*dom_fe, *ran_fe, *T,
+                                                      totelmat);
+         for (int j = 1; j < trace_face_integs.Size(); j++)
         {
-            trace_face_integs[k]->AssembleElementMatrix2(*trial_fes->GetFaceElement(i),
-                                                         *test_fes->GetFaceElement(i),
-                                                         *eltrans, elemmat);
-            elmat += elemmat;
+            trace_face_integs[j]->AssembleElementMatrix2(*dom_fe, *ran_fe, *T,
+                                                         elmat);
+            totelmat += elmat;
         }
-         mat->SetSubMatrix(test_vdofs, trial_vdofs, elmat, skip_zeros);
+         mat->SetSubMatrix(ran_vdofs, dom_vdofs, totelmat, skip_zeros);
      }
   }
 }
@@ -100,7 +100,7 @@ protected:
   /// Includes all by default.
   /// 0 - ignore attribute
   /// 1 - include attribute
-   Array<Array<int>*> domain_integs_marker; ///< Entries are not owned.
+   Array<Array<int>*>             domain_integs_marker;

   /// Set of Boundary Integrators to be applied.
   Array<BilinearFormIntegrator*> boundary_integs;
@@ -279,13 +279,13 @@ public:
   { return &boundary_face_integs_marker; }

   /// Returns a reference to: \f$ M_{ij} \f$
-   const real_t &operator()(int i, int j) { return (*mat)(i,j); }
+   const double &operator()(int i, int j) { return (*mat)(i,j); }

   /// Returns a reference to: \f$ M_{ij} \f$
-   virtual real_t &Elem(int i, int j);
+   virtual double &Elem(int i, int j);

   /// Returns constant reference to: \f$ M_{ij} \f$
-   virtual const real_t &Elem(int i, int j) const;
+   virtual const double &Elem(int i, int j) const;

   /// Matrix vector multiplication:  \f$ y = M x \f$
   virtual void Mult(const Vector &x, Vector &y) const;
@@ -297,7 +297,7 @@ public:
   { mat->Mult(x, y); mat_e->AddMult(x, y); }

   /// Add the matrix vector multiple to a vector:  \f$ y += a M x \f$
-   virtual void AddMult(const Vector &x, Vector &y, const real_t a = 1.0) const
+   virtual void AddMult(const Vector &x, Vector &y, const double a = 1.0) const
   { mat -> AddMult (x, y, a); }

   /** @brief Add the original uneliminated matrix vector multiple to a vector.
@@ -308,7 +308,7 @@ public:

   /// Add the matrix transpose vector multiplication:  \f$ y += a M^T x \f$
   virtual void AddMultTranspose(const Vector & x, Vector & y,
-                                 const real_t a = 1.0) const
+                                 const double a = 1.0) const
   { mat->AddMultTranspose(x, y, a); }

   /** @brief Add the original uneliminated matrix transpose vector
@@ -321,7 +321,7 @@ public:
   virtual void MultTranspose(const Vector & x, Vector & y) const;

   /// Compute \f$ y^T M x \f$
-   real_t InnerProduct(const Vector &x, const Vector &y) const
+   double InnerProduct(const Vector &x, const Vector &y) const
   { return mat->InnerProduct (x, y); }

   /// Returns a pointer to (approximation) of the matrix inverse:  \f$ M^{-1} \f$
@@ -423,7 +423,7 @@ public:
                             Array<int> &bdr_marker);

   /// Sets all sparse values of \f$ M \f$ and \f$ M_e \f$ to 'a'.
-   void operator=(const real_t a)
+   void operator=(const double a)
   {
      if (mat != NULL) { *mat = a; }
      if (mat_e != NULL) { *mat_e = a; }
@@ -614,7 +614,7 @@ public:
                             DiagonalPolicy dpolicy = DIAG_ONE);
   /// Perform elimination and set the diagonal entry to the given value
   void EliminateEssentialBCDiag(const Array<int> &bdr_attr_is_ess,
-                                 real_t value);
+                                 double value);

   /// Eliminate the given @a vdofs. NOTE: here, @a vdofs is a list of DOFs.
   /** In this case the eliminations are applied to the internal \f$ M \f$
@@ -643,7 +643,7 @@ public:
                                     DiagonalPolicy dpolicy = DIAG_ONE);
   /// Perform elimination and set the diagonal entry to the given value
   void EliminateEssentialBCFromDofsDiag(const Array<int> &ess_dofs,
-                                         real_t value);
+                                         double value);

   /** @brief Use the stored eliminated part of the matrix (see
       EliminateVDofs(const Array<int> &, DiagonalPolicy)) to modify the r.h.s.
@@ -652,7 +652,7 @@ public:
                            Vector &b);

   /// Compute inner product for full uneliminated matrix \f$ y^T M x + y^T M_e x \f$
-   real_t FullInnerProduct(const Vector &x, const Vector &y) const
+   double FullInnerProduct(const Vector &x, const Vector &y) const
   { return mat->InnerProduct(x, y) + mat_e->InnerProduct(x, y); }

   /// Update the @a FiniteElementSpace and delete all data associated with the old one.
@@ -722,13 +722,10 @@ protected:

   /// Domain integrators.
   Array<BilinearFormIntegrator*> domain_integs;
-   /// Entries are not owned.
-   Array<Array<int>*> domain_integs_marker;

   /// Boundary integrators.
   Array<BilinearFormIntegrator*> boundary_integs;
-   /// Entries are not owned.
-   Array<Array<int>*> boundary_integs_marker;
+   Array<Array<int>*> boundary_integs_marker; ///< Entries are not owned.

   /// Trace face (skeleton) integrators.
   Array<BilinearFormIntegrator*> trace_face_integs;
@@ -770,20 +767,20 @@ public:
                     MixedBilinearForm *mbf);

   /// Returns a reference to: \f$ M_{ij} \f$
-   virtual real_t &Elem(int i, int j);
+   virtual double &Elem(int i, int j);

   /// Returns a reference to: \f$ M_{ij} \f$
-   virtual const real_t &Elem(int i, int j) const;
+   virtual const double &Elem(int i, int j) const;

   /// Matrix multiplication: \f$ y = M x \f$
   virtual void Mult(const Vector & x, Vector & y) const;

   virtual void AddMult(const Vector & x, Vector & y,
-                        const real_t a = 1.0) const;
+                        const double a = 1.0) const;

   virtual void MultTranspose(const Vector & x, Vector & y) const;
   virtual void AddMultTranspose(const Vector & x, Vector & y,
-                                 const real_t a = 1.0) const;
+                                 const double a = 1.0) const;

   virtual MatrixInverse *Inverse() const;

@@ -808,16 +805,12 @@ public:
   /// Adds a domain integrator. Assumes ownership of @a bfi.
   void AddDomainIntegrator(BilinearFormIntegrator *bfi);

-   /// Adds a domain integrator. Assumes ownership of @a bfi.
-   void AddDomainIntegrator(BilinearFormIntegrator *bfi,
-                            Array<int> &elem_marker);
-
   /// Adds a boundary integrator. Assumes ownership of @a bfi.
   void AddBoundaryIntegrator(BilinearFormIntegrator *bfi);

   /// Adds a boundary integrator. Assumes ownership of @a bfi.
-   void AddBoundaryIntegrator(BilinearFormIntegrator * bfi,
-                              Array<int> &bdr_marker);
+   void AddBoundaryIntegrator (BilinearFormIntegrator * bfi,
+                               Array<int> &bdr_marker);

   /** @brief Add a trace face integrator. Assumes ownership of @a bfi.

@@ -827,18 +820,14 @@ public:
   void AddTraceFaceIntegrator(BilinearFormIntegrator *bfi);

   /// Adds a boundary trace face integrator. Assumes ownership of @a bfi.
-   void AddBdrTraceFaceIntegrator(BilinearFormIntegrator * bfi);
+   void AddBdrTraceFaceIntegrator (BilinearFormIntegrator * bfi);

   /// Adds a boundary trace face integrator. Assumes ownership of @a bfi.
-   void AddBdrTraceFaceIntegrator(BilinearFormIntegrator * bfi,
-                                  Array<int> &bdr_marker);
+   void AddBdrTraceFaceIntegrator (BilinearFormIntegrator * bfi,
+                                   Array<int> &bdr_marker);

   /// Access all integrators added with AddDomainIntegrator().
   Array<BilinearFormIntegrator*> *GetDBFI() { return &domain_integs; }
-   /** @brief Access all domain markers added with AddDomainIntegrator().
-       If no marker was specified when the integrator was added, the
-       corresponding pointer (to Array<int>) will be NULL. */
-   Array<Array<int>*> *GetDBFI_Marker() { return &domain_integs_marker; }

   /// Access all integrators added with AddBoundaryIntegrator().
   Array<BilinearFormIntegrator*> *GetBBFI() { return &boundary_integs; }
@@ -860,7 +849,7 @@ public:
   { return &boundary_trace_face_integs_marker; }

   /// Sets all sparse values of \f$ M \f$ to @a a.
-   void operator=(const real_t a) { *mat = a; }
+   void operator=(const double a) { *mat = a; }

   /// Set the desired assembly level. The default is AssemblyLevel::LEGACY.
   /** This method must be called before assembly. */
@@ -1076,9 +1065,6 @@ public:
   /// Adds a domain interpolator. Assumes ownership of @a di.
   void AddDomainInterpolator(DiscreteInterpolator *di)
   { AddDomainIntegrator(di); }
-   void AddDomainInterpolator(DiscreteInterpolator *di,
-                              Array<int> &elem_marker)
-   { AddDomainIntegrator(di, elem_marker); }

   /// Adds a trace face interpolator. Assumes ownership of @a di.
   void AddTraceFaceInterpolator(DiscreteInterpolator *di)
@@ -1086,7 +1072,6 @@ public:

   /// Access all interpolators added with AddDomainInterpolator().
   Array<BilinearFormIntegrator*> *GetDI() { return &domain_integs; }
-   Array<Array<int>*> *GetDI_Marker() { return &domain_integs_marker; }

   /// Set the desired assembly level. The default is AssemblyLevel::FULL.
   /** This method must be called before assembly. */
@@ -255,7 +255,9 @@ PABilinearFormExtension::PABilinearFormExtension(BilinearForm *form)
 void PABilinearFormExtension::SetupRestrictionOperators(const L2FaceValues m)
 {
   if ( Device::Allows(Backend::CEED_MASK) ) { return; }
-   ElementDofOrdering ordering = GetEVectorOrdering(*a->FESpace());
+   ElementDofOrdering ordering = UsesTensorBasis(*a->FESpace())?
+                                 ElementDofOrdering::LEXICOGRAPHIC:
+                                 ElementDofOrdering::NATIVE;
   elem_restrict = trial_fes->GetElementRestriction(ordering);
   if (elem_restrict)
   {
@@ -301,7 +303,7 @@ void PABilinearFormExtension::SetupRestrictionOperators(const L2FaceValues m)
      std::unordered_map<int,int> f_to_be;
      for (int i = 0; i < mesh.GetNBE(); ++i)
      {
-         const int f = mesh.GetBdrElementFaceIndex(i);
+         const int f = mesh.GetBdrElementEdgeIndex(i);
         f_to_be[f] = i;
      }
      const int nf_bdr = trial_fes->GetNFbyType(FaceType::Boundary);
@@ -789,7 +791,7 @@ void EABilinearFormExtension::Mult(const Vector &x, Vector &y) const
      {
         const int e = glob_j/NDOFS;
         const int j = glob_j%NDOFS;
-         real_t res = 0.0;
+         double res = 0.0;
         for (int i = 0; i < NDOFS; i++)
         {
            res += A(i, j, e)*X(i, e);
@@ -824,7 +826,7 @@ void EABilinearFormExtension::Mult(const Vector &x, Vector &y) const
            {
               const int f = glob_j/NDOFS;
               const int j = glob_j%NDOFS;
-               real_t res = 0.0;
+               double res = 0.0;
               for (int i = 0; i < NDOFS; i++)
               {
                  res += A_int(i, j, 0, f)*X(i, 0, f);
@@ -843,7 +845,7 @@ void EABilinearFormExtension::Mult(const Vector &x, Vector &y) const
         {
            const int f = glob_j/NDOFS;
            const int j = glob_j%NDOFS;
-            real_t res = 0.0;
+            double res = 0.0;
            for (int i = 0; i < NDOFS; i++)
            {
               res += A_ext(i, j, 0, f)*X(i, 0, f);
@@ -880,7 +882,7 @@ void EABilinearFormExtension::Mult(const Vector &x, Vector &y) const
         {
            const int f = glob_j/NDOFS;
            const int j = glob_j%NDOFS;
-            real_t res = 0.0;
+            double res = 0.0;
            for (int i = 0; i < NDOFS; i++)
            {
               res += A(i, j, f)*X(i, f);
@@ -917,7 +919,7 @@ void EABilinearFormExtension::MultTranspose(const Vector &x, Vector &y) const
      {
         const int e = glob_j/NDOFS;
         const int j = glob_j%NDOFS;
-         real_t res = 0.0;
+         double res = 0.0;
         for (int i = 0; i < NDOFS; i++)
         {
            res += A(j, i, e)*X(i, e);
@@ -952,7 +954,7 @@ void EABilinearFormExtension::MultTranspose(const Vector &x, Vector &y) const
            {
               const int f = glob_j/NDOFS;
               const int j = glob_j%NDOFS;
-               real_t res = 0.0;
+               double res = 0.0;
               for (int i = 0; i < NDOFS; i++)
               {
                  res += A_int(j, i, 0, f)*X(i, 0, f);
@@ -971,7 +973,7 @@ void EABilinearFormExtension::MultTranspose(const Vector &x, Vector &y) const
         {
            const int f = glob_j/NDOFS;
            const int j = glob_j%NDOFS;
-            real_t res = 0.0;
+            double res = 0.0;
            for (int i = 0; i < NDOFS; i++)
            {
               res += A_ext(j, i, 1, f)*X(i, 0, f);
@@ -1008,7 +1010,7 @@ void EABilinearFormExtension::MultTranspose(const Vector &x, Vector &y) const
         {
            const int f = glob_j/NDOFS;
            const int j = glob_j%NDOFS;
-            real_t res = 0.0;
+            double res = 0.0;
            for (int i = 0; i < NDOFS; i++)
            {
               res += A(j, i, f)*X(i, f);
@@ -1436,7 +1438,7 @@ void PAMixedBilinearFormExtension::SetupMultInputs(
   const Operator *elem_restrict_y,
   Vector &y,
   Vector &localY,
-   const real_t c) const
+   const double c) const
 {
   // * G operation: localX = c*local(x)
   if (elem_restrict_x)
@@ -1476,7 +1478,7 @@ void PAMixedBilinearFormExtension::Mult(const Vector &x, Vector &y) const
 }

 void PAMixedBilinearFormExtension::AddMult(const Vector &x, Vector &y,
-                                           const real_t c) const
+                                           const double c) const
 {
   Array<BilinearFormIntegrator*> &integrators = *a->GetDBFI();
   const int iSz = integrators.Size();
@@ -1508,7 +1510,7 @@ void PAMixedBilinearFormExtension::MultTranspose(const Vector &x,
 }

 void PAMixedBilinearFormExtension::AddMultTranspose(const Vector &x, Vector &y,
-                                                    const real_t c) const
+                                                    const double c) const
 {
   Array<BilinearFormIntegrator*> &integrators = *a->GetDBFI();
   const int iSz = integrators.Size();
@@ -1642,7 +1644,7 @@ void PADiscreteLinearOperatorExtension::Assemble()
 }

 void PADiscreteLinearOperatorExtension::AddMult(
-   const Vector &x, Vector &y, const real_t c) const
+   const Vector &x, Vector &y, const double c) const
 {
   Array<BilinearFormIntegrator*> &integrators = *a->GetDBFI();
   const int iSz = integrators.Size();
@@ -1675,7 +1677,7 @@ void PADiscreteLinearOperatorExtension::AddMult(
 }

 void PADiscreteLinearOperatorExtension::AddMultTranspose(
-   const Vector &x, Vector &y, const real_t c) const
+   const Vector &x, Vector &y, const double c) const
 {
   Array<BilinearFormIntegrator*> &integrators = *a->GetDBFI();
   const int iSz = integrators.Size();
@@ -248,7 +248,7 @@ protected:
   void SetupMultInputs(const Operator *elem_restrict_x,
                        const Vector &x, Vector &localX,
                        const Operator *elem_restrict_y,
-                        Vector &y, Vector &localY, const real_t c) const;
+                        Vector &y, Vector &localY, const double c) const;

 public:
   PAMixedBilinearFormExtension(MixedBilinearForm *form);
@@ -277,11 +277,11 @@ public:
   /// y = A*x
   void Mult(const Vector &x, Vector &y) const;
   /// y += c*A*x
-   void AddMult(const Vector &x, Vector &y, const real_t c=1.0) const;
+   void AddMult(const Vector &x, Vector &y, const double c=1.0) const;
   /// y = A^T*x
   void MultTranspose(const Vector &x, Vector &y) const;
   /// y += c*A^T*x
-   void AddMultTranspose(const Vector &x, Vector &y, const real_t c=1.0) const;
+   void AddMultTranspose(const Vector &x, Vector &y, const double c=1.0) const;
   /// Assemble the diagonal of ADA^T for a diagonal vector D.
   void AssembleDiagonal_ADAt(const Vector &D, Vector &diag) const;

@@ -305,9 +305,9 @@ public:
   /// Partial assembly of all internal integrators
   void Assemble();

-   void AddMult(const Vector &x, Vector &y, const real_t c=1.0) const;
+   void AddMult(const Vector &x, Vector &y, const double c=1.0) const;

-   void AddMultTranspose(const Vector &x, Vector &y, const real_t c=1.0) const;
+   void AddMultTranspose(const Vector &x, Vector &y, const double c=1.0) const;

   void FormRectangularSystemOperator(const Array<int>&, const Array<int>&,
                                      OperatorHandle& A);
@@ -14,7 +14,6 @@
 #include "fem.hpp"
 #include <cmath>
 #include <algorithm>
-#include <memory>

 using namespace std;

@@ -498,7 +497,7 @@ void MixedScalarIntegrator::AssembleElementMatrix2(
      this->CalcTestShape(test_fe, Trans, test_shape);
      this->CalcTrialShape(trial_fe, Trans, trial_shape);

-      real_t w = Trans.Weight() * ip.weight;
+      double w = Trans.Weight() * ip.weight;

      if (Q)
      {
@@ -592,7 +591,7 @@ void MixedVectorIntegrator::AssembleElementMatrix2(
         this->CalcTrialShape(trial_fe, Trans, trial_shape);
      }

-      real_t w = Trans.Weight() * ip.weight;
+      double w = Trans.Weight() * ip.weight;

      if (MQ)
      {
@@ -706,7 +705,7 @@ void MixedScalarVectorIntegrator::AssembleElementMatrix2(
   int sca_nd = sca_fe->GetDof();
   int vec_nd = vec_fe->GetDof();
   int vdim = GetVDim(*vec_fe);
-   real_t vtmp;
+   double vtmp;

   MFEM_VERIFY(VQ->GetVDim() == vdim, "MixedScalarVectorIntegrator: "
               "Dimensions of VectorCoefficient and Vector-valued basis "
@@ -745,7 +744,7 @@ void MixedScalarVectorIntegrator::AssembleElementMatrix2(
      this->CalcShape(*sca_fe, Trans, shape);
      this->CalcVShape(*vec_fe, Trans, vshape);

-      real_t w = Trans.Weight() * ip.weight;
+      double w = Trans.Weight() * ip.weight;

      VQ->Eval(V, Trans, ip);
      V *= w;
@@ -770,7 +769,7 @@ void GradientIntegrator::AssembleElementMatrix2(
   dim = test_fe.GetDim();
   int trial_dof = trial_fe.GetDof();
   int test_dof = test_fe.GetDof();
-   real_t c;
+   double c;
   Vector d_col;

   dshape.SetSize(trial_dof, dim);
@@ -788,12 +787,12 @@ void GradientIntegrator::AssembleElementMatrix2(
   for (int i = 0; i < ir->GetNPoints(); i++)
   {
      const IntegrationPoint &ip = ir->IntPoint(i);
-      Trans.SetIntPoint(&ip);

-      CalcAdjugate(Trans.Jacobian(), Jadj);
-
-      test_fe.CalcPhysShape(Trans, shape);
      trial_fe.CalcDShape(ip, dshape);
+      test_fe.CalcShape(ip, shape);
+
+      Trans.SetIntPoint(&ip);
+      CalcAdjugate(Trans.Jacobian(), Jadj);

      Mult(dshape, Jadj, gshape);

@@ -837,7 +836,7 @@ void DiffusionIntegrator::AssembleElementMatrix
   dim = el.GetDim();
   int spaceDim = Trans.GetSpaceDim();
   bool square = (dim == spaceDim);
-   real_t w;
+   double w;

   if (VQ)
   {
@@ -931,7 +930,7 @@ void DiffusionIntegrator::AssembleElementMatrix2(
   dim = trial_fe.GetDim();
   int spaceDim = Trans.GetSpaceDim();
   bool square = (dim == spaceDim);
-   real_t w;
+   double w;

   if (VQ)
   {
@@ -1013,7 +1012,7 @@ void DiffusionIntegrator::AssembleElementVector(
   int nd = el.GetDof();
   dim = el.GetDim();
   int spaceDim = Tr.GetSpaceDim();
-   real_t w;
+   double w;

   if (VQ)
   {
@@ -1187,7 +1186,7 @@ void DiffusionIntegrator::ComputeElementFlux
   }
 }

-real_t DiffusionIntegrator::ComputeFluxEnergy
+double DiffusionIntegrator::ComputeFluxEnergy
 ( const FiniteElement &fluxelem, ElementTransformation &Trans,
  Vector &flux, Vector* d_energy)
 {
@@ -1210,7 +1209,7 @@ real_t DiffusionIntegrator::ComputeFluxEnergy
   int order = 2 * fluxelem.GetOrder(); // <--
   const IntegrationRule *ir = &IntRules.Get(fluxelem.GetGeomType(), order);

-   real_t energy = 0.0;
+   double energy = 0.0;
   if (d_energy) { *d_energy = 0.0; }

   for (int i = 0; i < ir->GetNPoints(); i++)
@@ -1228,7 +1227,7 @@ real_t DiffusionIntegrator::ComputeFluxEnergy
      }

      Trans.SetIntPoint(&ip);
-      real_t w = Trans.Weight() * ip.weight;
+      double w = Trans.Weight() * ip.weight;

      if (MQ)
      {
@@ -1243,7 +1242,7 @@ real_t DiffusionIntegrator::ComputeFluxEnergy
      }
      else
      {
-         real_t e = (pointflux * pointflux);
+         double e = (pointflux * pointflux);
         if (Q) { e *= Q->Eval(Trans, ip); }
         energy += w * e;
      }
@@ -1291,7 +1290,7 @@ void MassIntegrator::AssembleElementMatrix
 {
   int nd = el.GetDof();
   // int dim = el.GetDim();
-   real_t w;
+   double w;

 #ifdef MFEM_THREAD_SAFE
   Vector shape;
@@ -1325,7 +1324,7 @@ void MassIntegrator::AssembleElementMatrix2(
 {
   int tr_nd = trial_fe.GetDof();
   int te_nd = test_fe.GetDof();
-   real_t w;
+   double w;

 #ifdef MFEM_THREAD_SAFE
   Vector shape, te_shape;
@@ -1341,11 +1340,10 @@ void MassIntegrator::AssembleElementMatrix2(
   for (int i = 0; i < ir->GetNPoints(); i++)
   {
      const IntegrationPoint &ip = ir->IntPoint(i);
+      trial_fe.CalcShape(ip, shape);
+      test_fe.CalcShape(ip, te_shape);
+
      Trans.SetIntPoint (&ip);
-
-      trial_fe.CalcPhysShape(Trans, shape);
-      test_fe.CalcPhysShape(Trans, te_shape);
-
      w = Trans.Weight() * ip.weight;
      if (Q)
      {
@@ -1380,7 +1378,7 @@ void BoundaryMassIntegrator::AssembleFaceMatrix(
               "support for interior faces is not implemented");

   int nd1 = el1.GetDof();
-   real_t w;
+   double w;

 #ifdef MFEM_THREAD_SAFE
   Vector shape;
@@ -1499,15 +1497,15 @@ void GroupConvectionIntegrator::AssembleElementMatrix(

      Mult(dshape, adjJ, grad);

-      real_t w = alpha * ip.weight;
+      double w = alpha * ip.weight;

      // elmat(k,l) += \sum_s w*shape(k)*Q_nodal(s,k)*grad(l,s)
      for (int k = 0; k < nd; k++)
      {
-         real_t wsk = w*shape(k);
+         double wsk = w*shape(k);
         for (int l = 0; l < nd; l++)
         {
-            real_t a = 0.0;
+            double a = 0.0;
            for (int s = 0; s < dim; s++)
            {
               a += Q_nodal(s,k)*grad(l,s);
@@ -1540,7 +1538,7 @@ void VectorMassIntegrator::AssembleElementMatrix
   int nd = el.GetDof();
   int spaceDim = Trans.GetSpaceDim();

-   real_t norm;
+   double norm;

   // If vdim is not set, set it to the space dimension
   vdim = (vdim == -1) ? spaceDim : vdim;
@@ -1622,7 +1620,7 @@ void VectorMassIntegrator::AssembleElementMatrix2(
   int tr_nd = trial_fe.GetDof();
   int te_nd = test_fe.GetDof();

-   real_t norm;
+   double norm;

   // If vdim is not set, set it to the space dimension
   vdim = (vdim == -1) ? Trans.GetSpaceDim() : vdim;
@@ -1729,7 +1727,7 @@ void VectorFEDivergenceIntegrator::AssembleElementMatrix2(
      trial_fe.CalcDivShape(ip, divshape);
      Trans.SetIntPoint(&ip);
      test_fe.CalcPhysShape(Trans, shape);
-      real_t w = ip.weight;
+      double w = ip.weight;
      if (Q)
      {
         Trans.SetIntPoint(&ip);
@@ -1810,7 +1808,7 @@ void VectorFEWeakDivergenceIntegrator::AssembleElementMatrix2(

      trial_fe.CalcVShape(Trans, vshape);

-      real_t w = ip.weight;
+      double w = ip.weight;

      if (Q)
      {
@@ -1900,7 +1898,7 @@ void VectorFECurlIntegrator::AssembleElementMatrix2(
         }
      }

-      real_t w = ip.weight;
+      double w = ip.weight;

      if (Q)
      {
@@ -1931,7 +1929,7 @@ void DerivativeIntegrator::AssembleElementMatrix2 (
   int spaceDim = Trans.GetSpaceDim();

   int i, l;
-   real_t det;
+   double det;

   elmat.SetSize (test_nd,trial_nd);
   dshape.SetSize (trial_nd,dim);
@@ -1994,7 +1992,7 @@ void CurlCurlIntegrator::AssembleElementMatrix
   int nd = el.GetDof();
   dim = el.GetDim();
   int dimc = el.GetCurlDim();
-   real_t w;
+   double w;

 #ifdef MFEM_THREAD_SAFE
   Vector D;
@@ -2067,7 +2065,7 @@ void CurlCurlIntegrator::AssembleElementMatrix2(const FiniteElement &trial_fe,
   int te_nd = test_fe.GetDof();
   dim = trial_fe.GetDim();
   int dimc = trial_fe.GetCurlDim();
-   real_t w;
+   double w;

 #ifdef MFEM_THREAD_SAFE
   Vector D;
@@ -2154,7 +2152,7 @@ void CurlCurlIntegrator
   // TODO: Q, wcoef?
 }

-real_t CurlCurlIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
+double CurlCurlIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
                                             ElementTransformation &Trans,
                                             Vector &flux, Vector *d_energy)
 {
@@ -2171,7 +2169,7 @@ real_t CurlCurlIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
   int order = 2 * fluxelem.GetOrder(); // <--
   const IntegrationRule &ir = IntRules.Get(fluxelem.GetGeomType(), order);

-   real_t energy = 0.0;
+   double energy = 0.0;
   if (d_energy) { *d_energy = 0.0; }

   Vector* pfluxes = NULL;
@@ -2189,9 +2187,9 @@ real_t CurlCurlIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
      // fluxelem.CalcVShape(ip, vshape);
      vshape.MultTranspose(flux, pointflux);

-      real_t w = Trans.Weight() * ip.weight;
+      double w = Trans.Weight() * ip.weight;

-      real_t e = w * (pointflux * pointflux);
+      double e = w * (pointflux * pointflux);

      if (Q)
      {
@@ -2293,7 +2291,7 @@ void VectorCurlCurlIntegrator::AssembleElementMatrix(

      Trans.SetIntPoint(&ip);
      CalcAdjugate(Trans.Jacobian(), Jadj);
-      real_t w = ip.weight / Trans.Weight();
+      double w = ip.weight / Trans.Weight();

      Mult(dshape_hat, Jadj, dshape);
      dshape.GradToCurl(curlshape);
@@ -2307,7 +2305,7 @@ void VectorCurlCurlIntegrator::AssembleElementMatrix(
   }
 }

-real_t VectorCurlCurlIntegrator::GetElementEnergy(
+double VectorCurlCurlIntegrator::GetElementEnergy(
   const FiniteElement &el, ElementTransformation &Tr, const Vector &elfun)
 {
   int dim = el.GetDim();
@@ -2332,7 +2330,7 @@ real_t VectorCurlCurlIntegrator::GetElementEnergy(
      ir = &IntRules.Get(el.GetGeomType(), order);
   }

-   real_t energy = 0.;
+   double energy = 0.;
   for (int i = 0; i < ir->GetNPoints(); i++)
   {
      const IntegrationPoint &ip = ir->IntPoint(i);
@@ -2342,20 +2340,20 @@ real_t VectorCurlCurlIntegrator::GetElementEnergy(

      Tr.SetIntPoint(&ip);
      CalcAdjugate(Tr.Jacobian(), Jadj);
-      real_t w = ip.weight / Tr.Weight();
+      double w = ip.weight / Tr.Weight();

      Mult(grad_hat, Jadj, grad);

      if (dim == 2)
      {
-         real_t curl = grad(0,1) - grad(1,0);
+         double curl = grad(0,1) - grad(1,0);
         w *= curl * curl;
      }
      else
      {
-         real_t curl_x = grad(2,1) - grad(1,2);
-         real_t curl_y = grad(0,2) - grad(2,0);
-         real_t curl_z = grad(1,0) - grad(0,1);
+         double curl_x = grad(2,1) - grad(1,2);
+         double curl_y = grad(0,2) - grad(2,0);
+         double curl_z = grad(1,0) - grad(0,1);
         w *= curl_x * curl_x + curl_y * curl_y + curl_z * curl_z;
      }

@@ -2405,7 +2403,7 @@ void MixedCurlIntegrator::AssembleElementMatrix2(
   shape.SetSize(test_dof);
   elmat = 0.0;

-   real_t c;
+   double c;
   Vector d_col;
   const IntegrationRule *ir = IntRule;

@@ -2438,7 +2436,7 @@ void MixedCurlIntegrator::AssembleElementMatrix2(

      for (int d = 0; d < dimc; ++d)
      {
-         real_t * curldata = &(curlshape.GetData())[d*trial_dof];
+         double * curldata = &(curlshape.GetData())[d*trial_dof];
         for (int jj = 0; jj < trial_dof; ++jj)
         {
            for (int ii = 0; ii < test_dof; ++ii)
@@ -2460,7 +2458,7 @@ void VectorFEMassIntegrator::AssembleElementMatrix(
   int spaceDim = Trans.GetSpaceDim();
   int vdim = std::max(spaceDim, el.GetRangeDim());

-   real_t w;
+   double w;

 #ifdef MFEM_THREAD_SAFE
   Vector D(DQ ? DQ->GetVDim() : 0);
@@ -2529,7 +2527,7 @@ void VectorFEMassIntegrator::AssembleElementMatrix2(
      int vdim = std::max(spaceDim, trial_fe.GetRangeDim());
      int trial_dof = trial_fe.GetDof();
      int test_dof = test_fe.GetDof();
-      real_t w;
+      double w;

 #ifdef MFEM_THREAD_SAFE
      DenseMatrix trial_vshape(trial_dof, spaceDim);
@@ -2589,7 +2587,7 @@ void VectorFEMassIntegrator::AssembleElementMatrix2(
               {
                  for (int k = 0; k < trial_dof; k++)
                  {
-                     real_t Kv = 0.0;
+                     double Kv = 0.0;
                     for (int vd = 0; vd < spaceDim; vd++)
                     {
                        Kv += K(d, vd) * trial_vshape(k, vd);
@@ -2628,7 +2626,7 @@ void VectorFEMassIntegrator::AssembleElementMatrix2(
      int test_vdim = std::max(spaceDim, test_fe.GetRangeDim());
      int trial_dof = trial_fe.GetDof();
      int test_dof = test_fe.GetDof();
-      real_t w;
+      double w;

 #ifdef MFEM_THREAD_SAFE
      DenseMatrix trial_vshape(trial_dof,trial_vdim);
@@ -2702,7 +2700,7 @@ void VectorDivergenceIntegrator::AssembleElementMatrix2(
   dim  = trial_fe.GetDim();
   int trial_dof = trial_fe.GetDof();
   int test_dof = test_fe.GetDof();
-   real_t c;
+   double c;

   dshape.SetSize (trial_dof, dim);
   gshape.SetSize (trial_dof, dim);
@@ -2759,7 +2757,7 @@ void DivDivIntegrator::AssembleElementMatrix(
   DenseMatrix &elmat)
 {
   int dof = el.GetDof();
-   real_t c;
+   double c;

 #ifdef MFEM_THREAD_SAFE
   Vector divshape(dof);
@@ -2804,7 +2802,7 @@ void DivDivIntegrator::AssembleElementMatrix2(
 {
   int tr_nd = trial_fe.GetDof();
   int te_nd = test_fe.GetDof();
-   real_t c;
+   double c;

 #ifdef MFEM_THREAD_SAFE
   Vector divshape(tr_nd);
@@ -2888,7 +2886,7 @@ void VectorDiffusionIntegrator::AssembleElementMatrix(
      el.CalcDShape(ip, dshape);

      Trans.SetIntPoint(&ip);
-      real_t w = Trans.Weight();
+      double w = Trans.Weight();
      w = ip.weight / (square ? w : w*w*w);
      // AdjugateJacobian = / adj(J),         if J is square
      //                    \ adj(J^t.J).J^t, otherwise
@@ -2973,7 +2971,7 @@ void VectorDiffusionIntegrator::AssembleElementVector(
      el.CalcDShape(ip, dshape);

      Tr.SetIntPoint(&ip);
-      real_t w = Tr.Weight();
+      double w = Tr.Weight();
      w = ip.weight / (square ? w : w*w*w);
      Mult(dshape, Tr.AdjugateJacobian(), dshapedxt);
      MultAAt(dshapedxt, pelmat);
@@ -3017,19 +3015,13 @@ void VectorDiffusionIntegrator::AssembleElementVector(
   }
 }

-ElasticityComponentIntegrator::ElasticityComponentIntegrator(
-   ElasticityIntegrator &parent_, int i_, int j_)
-   : parent(parent_),
-     i_block(i_),
-     j_block(j_)
-{ }

 void ElasticityIntegrator::AssembleElementMatrix(
   const FiniteElement &el, ElementTransformation &Trans, DenseMatrix &elmat)
 {
   int dof = el.GetDof();
   int dim = el.GetDim();
-   real_t w, L, M;
+   double w, L, M;

   MFEM_ASSERT(dim == Trans.GetSpaceDim(), "");

@@ -3114,7 +3106,7 @@ void ElasticityIntegrator::ComputeElementFlux(
   const int dof = el.GetDof();
   const int dim = el.GetDim();
   const int tdim = dim*(dim+1)/2; // num. entries in a symmetric tensor
-   real_t L, M;
+   double L, M;

   MFEM_ASSERT(dim == 2 || dim == 3,
               "dimension is not supported: dim = " << dim);
@@ -3128,7 +3120,7 @@ void ElasticityIntegrator::ComputeElementFlux(
   dshape.SetSize(dof, dim);
 #endif

-   real_t gh_data[9], grad_data[9];
+   double gh_data[9], grad_data[9];
   DenseMatrix gh(gh_data, dim, dim);
   DenseMatrix grad(grad_data, dim, dim);

@@ -3162,7 +3154,7 @@ void ElasticityIntegrator::ComputeElementFlux(

      // stress = 2*M*e(u) + L*tr(e(u))*I, where
      //   e(u) = (1/2)*(grad(u) + grad(u)^T)
-      const real_t M2 = 2.0*M;
+      const double M2 = 2.0*M;
      if (dim == 2)
      {
         L *= (grad(0,0) + grad(1,1));
@@ -3185,14 +3177,14 @@ void ElasticityIntegrator::ComputeElementFlux(
   }
 }

-real_t ElasticityIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
+double ElasticityIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
                                               ElementTransformation &Trans,
                                               Vector &flux, Vector *d_energy)
 {
   const int dof = fluxelem.GetDof();
   const int dim = fluxelem.GetDim();
   const int tdim = dim*(dim+1)/2; // num. entries in a symmetric tensor
-   real_t L, M;
+   double L, M;

   // The MFEM_ASSERT constraints in ElasticityIntegrator::ComputeElementFlux
   // are assumed here too.
@@ -3204,7 +3196,7 @@ real_t ElasticityIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
 #else
   Vector shape(dof);
 #endif
-   real_t pointstress_data[6];
+   double pointstress_data[6];
   Vector pointstress(pointstress_data, tdim);

   // View of the 'flux' vector as a (dof x tdim) matrix
@@ -3220,7 +3212,7 @@ real_t ElasticityIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
      ir = &IntRules.Get(fluxelem.GetGeomType(), order);
   }

-   real_t energy = 0.0;
+   double energy = 0.0;

   for (int i = 0; i < ir->GetNPoints(); i++)
   {
@@ -3230,7 +3222,7 @@ real_t ElasticityIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
      flux_mat.MultTranspose(shape, pointstress);

      Trans.SetIntPoint(&ip);
-      real_t w = Trans.Weight() * ip.weight;
+      double w = Trans.Weight() * ip.weight;

      M = mu->Eval(Trans, ip);
      if (lambda)
@@ -3254,19 +3246,19 @@ real_t ElasticityIntegrator::ComputeFluxEnergy(const FiniteElement &fluxelem,
      // Then from the first identity above we can find the strain:
      //    e = (1/(2*mu))*(s - lambda*tr(e)*I)

-      real_t pt_e; // point strain energy density
-      const real_t *s = pointstress_data;
+      double pt_e; // point strain energy density
+      const double *s = pointstress_data;
      if (dim == 2)
      {
         // s entries: s_xx, s_yy, s_xy
-         const real_t tr_e = (s[0] + s[1])/(2*(M + L));
+         const double tr_e = (s[0] + s[1])/(2*(M + L));
         L *= tr_e;
         pt_e = (0.25/M)*(s[0]*(s[0] - L) + s[1]*(s[1] - L) + 2*s[2]*s[2]);
      }
      else // (dim == 3)
      {
         // s entries: s_xx, s_yy, s_zz, s_xy, s_xz, s_yz
-         const real_t tr_e = (s[0] + s[1] + s[2])/(2*M + 3*L);
+         const double tr_e = (s[0] + s[1] + s[2])/(2*M + 3*L);
         L *= tr_e;
         pt_e = (0.25/M)*(s[0]*(s[0] - L) + s[1]*(s[1] - L) + s[2]*(s[2] - L) +
                          2*(s[3]*s[3] + s[4]*s[4] + s[5]*s[5]));
@@ -3285,7 +3277,7 @@ void DGTraceIntegrator::AssembleFaceMatrix(const FiniteElement &el1,
 {
   int ndof1, ndof2;

-   real_t un, a, b, w;
+   double un, a, b, w;

   dim = el1.GetDim();
   ndof1 = el1.GetDof();
@@ -3358,7 +3350,7 @@ void DGTraceIntegrator::AssembleFaceMatrix(const FiniteElement &el1,

      if (rho)
      {
-         real_t rho_p;
+         double rho_p;
         if (un >= 0.0 && ndof2)
         {
            rho_p = rho->Eval(*Trans.Elem2, eip2);
@@ -3425,7 +3417,7 @@ void DGDiffusionIntegrator::AssembleFaceMatrix(
 {
   int dim, ndof1, ndof2, ndofs;
   bool kappa_is_nonzero = (kappa != 0.);
-   real_t w, wq = 0.0;
+   double w, wq = 0.0;

   dim = el1.GetDim();
   ndof1 = el1.GetDof();
@@ -3600,7 +3592,7 @@ void DGDiffusionIntegrator::AssembleFaceMatrix(
         wq *= kappa;
         for (int i = 0; i < ndof1; i++)
         {
-            const real_t wsi = wq*shape1(i);
+            const double wsi = wq*shape1(i);
            for (int j = 0; j <= i; j++)
            {
               jmat(i, j) += wsi * shape1(j);
@@ -3611,7 +3603,7 @@ void DGDiffusionIntegrator::AssembleFaceMatrix(
            for (int i = 0; i < ndof2; i++)
            {
               const int i2 = ndof1 + i;
-               const real_t wsi = wq*shape2(i);
+               const double wsi = wq*shape2(i);
               for (int j = 0; j < ndof1; j++)
               {
                  jmat(i2, j) -= wsi * shape1(j);
@@ -3632,7 +3624,7 @@ void DGDiffusionIntegrator::AssembleFaceMatrix(
      {
         for (int j = 0; j < i; j++)
         {
-            real_t aij = elmat(i,j), aji = elmat(j,i), mij = jmat(i,j);
+            double aij = elmat(i,j), aji = elmat(j,i), mij = jmat(i,j);
            elmat(i,j) = sigma*aji - aij + mij;
            elmat(j,i) = sigma*aij - aji + mij;
         }
@@ -3645,7 +3637,7 @@ void DGDiffusionIntegrator::AssembleFaceMatrix(
      {
         for (int j = 0; j < i; j++)
         {
-            real_t aij = elmat(i,j), aji = elmat(j,i);
+            double aij = elmat(i,j), aji = elmat(j,i);
            elmat(i,j) = sigma*aji - aij;
            elmat(j,i) = sigma*aij - aji;
         }
@@ -3659,7 +3651,7 @@ void DGDiffusionIntegrator::AssembleFaceMatrix(
 void DGElasticityIntegrator::AssembleBlock(
   const int dim, const int row_ndofs, const int col_ndofs,
   const int row_offset, const int col_offset,
-   const real_t jmatcoef, const Vector &col_nL, const Vector &col_nM,
+   const double jmatcoef, const Vector &col_nL, const Vector &col_nM,
   const Vector &row_shape, const Vector &col_shape,
   const Vector &col_dshape_dnM, const DenseMatrix &col_dshape,
   DenseMatrix &elmat, DenseMatrix &jmat)
@@ -3668,12 +3660,12 @@ void DGElasticityIntegrator::AssembleBlock(
   {
      for (int jdof = 0; jdof < col_ndofs; ++jdof, ++j)
      {
-         const real_t t2 = col_dshape_dnM(jdof);
+         const double t2 = col_dshape_dnM(jdof);
         for (int im = 0, i = row_offset; im < dim; ++im)
         {
-            const real_t t1 = col_dshape(jdof, jm) * col_nL(im);
-            const real_t t3 = col_dshape(jdof, im) * col_nM(jm);
-            const real_t tt = t1 + ((im == jm) ? t2 : 0.0) + t3;
+            const double t1 = col_dshape(jdof, jm) * col_nL(im);
+            const double t3 = col_dshape(jdof, im) * col_nM(jm);
+            const double tt = t1 + ((im == jm) ? t2 : 0.0) + t3;
            for (int idof = 0; idof < row_ndofs; ++idof, ++i)
            {
               elmat(i, j) += row_shape(idof) * tt;
@@ -3690,7 +3682,7 @@ void DGElasticityIntegrator::AssembleBlock(
      const int io = row_offset + d*row_ndofs;
      for (int jdof = 0, j = jo; jdof < col_ndofs; ++jdof, ++j)
      {
-         const real_t sj = jmatcoef * col_shape(jdof);
+         const double sj = jmatcoef * col_shape(jdof);
         for (int i = max(io,j), idof = i - io; idof < row_ndofs; ++idof, ++i)
         {
            jmat(i, j) += row_shape(idof) * sj;
@@ -3790,7 +3782,7 @@ void DGElasticityIntegrator::AssembleFaceMatrix(
         CalcOrtho(Trans.Jacobian(), nor);
      }

-      real_t w, wLM;
+      double w, wLM;
      if (ndofs2)
      {
         el2.CalcShape(eip2, shape2);
@@ -3799,9 +3791,9 @@ void DGElasticityIntegrator::AssembleFaceMatrix(
         Mult(dshape2, adjJ, dshape2_ps);

         w = ip.weight/2;
-         const real_t w2 = w / Trans.Elem2->Weight();
-         const real_t wL2 = w2 * lambda->Eval(*Trans.Elem2, eip2);
-         const real_t wM2 = w2 * mu->Eval(*Trans.Elem2, eip2);
+         const double w2 = w / Trans.Elem2->Weight();
+         const double wL2 = w2 * lambda->Eval(*Trans.Elem2, eip2);
+         const double wM2 = w2 * mu->Eval(*Trans.Elem2, eip2);
         nL2.Set(wL2, nor);
         nM2.Set(wM2, nor);
         wLM = (wL2 + 2.0*wM2);
@@ -3814,16 +3806,16 @@ void DGElasticityIntegrator::AssembleFaceMatrix(
      }

      {
-         const real_t w1 = w / Trans.Elem1->Weight();
-         const real_t wL1 = w1 * lambda->Eval(*Trans.Elem1, eip1);
-         const real_t wM1 = w1 * mu->Eval(*Trans.Elem1, eip1);
+         const double w1 = w / Trans.Elem1->Weight();
+         const double wL1 = w1 * lambda->Eval(*Trans.Elem1, eip1);
+         const double wM1 = w1 * mu->Eval(*Trans.Elem1, eip1);
         nL1.Set(wL1, nor);
         nM1.Set(wM1, nor);
         wLM += (wL1 + 2.0*wM1);
         dshape1_ps.Mult(nM1, dshape1_dnM);
      }

-      const real_t jmatcoef = kappa * (nor*nor) * wLM;
+      const double jmatcoef = kappa * (nor*nor) * wLM;

      // (1,1) block
      AssembleBlock(
@@ -3856,7 +3848,7 @@ void DGElasticityIntegrator::AssembleFaceMatrix(
      {
         for (int j = 0; j < i; ++j)
         {
-            real_t aij = elmat(i,j), aji = elmat(j,i), mij = jmat(i,j);
+            double aij = elmat(i,j), aji = elmat(j,i), mij = jmat(i,j);
            elmat(i,j) = alpha*aji - aij + mij;
            elmat(j,i) = alpha*aij - aji + mij;
         }
@@ -3869,7 +3861,7 @@ void DGElasticityIntegrator::AssembleFaceMatrix(
      {
         for (int j = 0; j < i; ++j)
         {
-            real_t aij = elmat(i,j), aji = elmat(j,i);
+            double aij = elmat(i,j), aji = elmat(j,i);
            elmat(i,j) = alpha*aji - aij;
            elmat(j,i) = alpha*aij - aji;
         }
@@ -3887,7 +3879,7 @@ void TraceJumpIntegrator::AssembleFaceMatrix(
   int i, j, face_ndof, ndof1, ndof2;
   int order;

-   real_t w;
+   double w;

   face_ndof = trial_face_fe.GetDof();
   ndof1 = test_fe1.GetDof();
@@ -4095,7 +4087,7 @@ void TraceIntegrator::AssembleTraceFaceMatrix(int elem,
      MFEM_VERIFY(elem == Trans.Elem2->ElementNo, "Elem != Trans.Elem2->ElementNo");
   }

-   real_t scale = 1.0;
+   double scale = 1.0;
   if (iel != elem) { scale = -1.; }
   for (int p = 0; p < ir->GetNPoints(); p++)
   {
@@ -4161,7 +4153,7 @@ void NormalTraceIntegrator::AssembleTraceFaceMatrix(int elem,
      MFEM_VERIFY(elem == Trans.Elem2->ElementNo, "Elem != Trans.Elem2->ElementNo");
   }

-   real_t scale = 1.0;
+   double scale = 1.0;
   if (iel != elem) { scale = -1.; }

   for (int p = 0; p < ir->GetNPoints(); p++)
@@ -4240,7 +4232,7 @@ void TangentTraceIntegrator::AssembleTraceFaceMatrix(int elem,
      MFEM_VERIFY(elem == Trans.Elem2->ElementNo, "Elem != Trans.Elem2->ElementNo");
   }

-   real_t scale = 1.0;
+   double scale = 1.0;
   if (iel != elem) { scale = -1.; }
   for (int p = 0; p < ir->GetNPoints(); p++)
   {
@@ -4264,7 +4256,7 @@ void TangentTraceIntegrator::AssembleTraceFaceMatrix(int elem,
      // rotate
      cross_product(normal, shape, shape_n);

-      const real_t w = scale*ip.weight;
+      const double w = scale*ip.weight;
      AddMult_a_ABt(w,shape_n, face_shape, elmat);
   }
 }
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Tom Stitt	cf1c58ee1c	Merge remote-tracking branch 'origin/hypre-runtime-compute-policy' into apps-dev	2023-10-27 09:22:16 -07:00
Tom Stitt	02579a1d23	Merge remote-tracking branch 'origin/feature/askinner/hdiv-saddle-point-solver' into apps-dev	2023-10-27 09:22:12 -07:00
Tom Stitt	66d9ead7b1	Merge remote-tracking branch 'origin/master' into hypre-runtime-compute-policy	2023-10-27 09:03:44 -07:00
Tom Stitt	4115a9ad5d	handle more HYPRE_USING_{GPU,HIP,CUDA}	2023-08-29 21:16:35 -07:00
Tom Stitt	a8cb5babce	add support for runtime hypre compute policy	2023-08-25 14:36:14 -07:00