Files
mfem/miniapps/meshing/mesh-optimizer.cpp
T

1389 lines
47 KiB
C++

// Copyright (c) 2010, Lawrence Livermore National Security, LLC. Produced at
// the Lawrence Livermore National Laboratory. LLNL-CODE-443211. All Rights
// reserved. See file COPYRIGHT for details.
//
// This file is part of the MFEM library. For more information and source code
// availability see http://mfem.org.
//
// MFEM is free software; you can redistribute it and/or modify it under the
// terms of the GNU Lesser General Public License (as published by the Free
// Software Foundation) version 2.1 dated February 1999.
//
// --------------------------------------------------
// Mesh Optimizer Miniapp: Optimize high-order meshes
// --------------------------------------------------
//
// This miniapp performs mesh optimization using the Target-Matrix Optimization
// Paradigm (TMOP) by P.Knupp et al., and a global variational minimization
// approach. It minimizes the quantity sum_T int_T mu(J(x)), where T are the
// target (ideal) elements, J is the Jacobian of the transformation from the
// target to the physical element, and mu is the mesh quality metric. This
// metric can measure shape, size or alignment of the region around each
// quadrature point. The combination of targets & quality metrics is used to
// optimize the physical node positions, i.e., they must be as close as possible
// to the shape / size / alignment of their targets. This code also demonstrates
// a possible use of nonlinear operators (the class TMOP_QualityMetric, defining
// mu(J), and the class TMOP_Integrator, defining int mu(J)), as well as their
// coupling to Newton methods for solving minimization problems. Note that the
// utilized Newton methods are oriented towards avoiding invalid meshes with
// negative Jacobian determinants. Each Newton step requires the inversion of a
// Jacobian matrix, which is done through an inner linear solver.
//
// Compile with: make mesh-optimizer
//
// Sample runs:
// Adapted analytic Hessian:
// mesh-optimizer -m square01.mesh -o 2 -rs 2 -mid 2 -tid 4 -ni 200 -ls 2 -li 100 -bnd -qt 1 -qo 8
// Adapted discrete size:
// mesh-optimizer -m square01.mesh -o 2 -rs 2 -mid 7 -tid 5 -ni 200 -ls 2 -li 100 -bnd -qt 1 -qo 8
//
// Blade shape:
// mesh-optimizer -m blade.mesh -o 4 -rs 0 -mid 2 -tid 1 -ni 200 -ls 2 -li 100 -bnd -qt 1 -qo 8
// Blade limited shape:
// mesh-optimizer -m blade.mesh -o 4 -rs 0 -mid 2 -tid 1 -ni 200 -ls 2 -li 100 -bnd -qt 1 -qo 8 -lc 5000
// ICF shape and equal size:
// mesh-optimizer -o 3 -rs 0 -mid 9 -tid 2 -ni 200 -ls 2 -li 100 -bnd -qt 1 -qo 8
// ICF shape and initial size:
// mesh-optimizer -o 3 -rs 0 -mid 9 -tid 3 -ni 100 -ls 2 -li 100 -bnd -qt 1 -qo 8
// ICF shape:
// mesh-optimizer -o 3 -rs 0 -mid 1 -tid 1 -ni 100 -ls 2 -li 100 -bnd -qt 1 -qo 8
// ICF limited shape:
// mesh-optimizer -o 3 -rs 0 -mid 1 -tid 1 -ni 100 -ls 2 -li 100 -bnd -qt 1 -qo 8 -lc 10
// ICF combo shape + size (rings, slow convergence):
// mesh-optimizer -o 3 -rs 0 -mid 1 -tid 1 -ni 1000 -ls 2 -li 100 -bnd -qt 1 -qo 8 -cmb
// 3D pinched sphere shape (the mesh is in the mfem/data GitHub repository):
// * mesh-optimizer -m ../../../mfem_data/ball-pert.mesh -o 4 -rs 0 -mid 303 -tid 1 -ni 20 -ls 2 -li 500 -fix-bnd
// 2D non-conforming shape and equal size:
// mesh-optimizer -m ./amr-quad-q2.mesh -o 2 -rs 1 -mid 9 -tid 2 -ni 200 -ls 2 -li 100 -bnd -qt 1 -qo 8
#include "../../mfem.hpp"
#include <fstream>
#include <iostream>
using namespace mfem;
using namespace std;
class HessianCoefficient : public MatrixCoefficient
{
private:
int type;
int typemod = 1;
public:
HessianCoefficient(int dim, int type_)
: MatrixCoefficient(dim), typemod(type_) { }
virtual void SetType(int typemod_) { typemod = typemod_; }
virtual void Eval(DenseMatrix &K, ElementTransformation &T,
const IntegrationPoint &ip)
{
Vector pos(3);
T.Transform(ip, pos);
(this)->Eval(K,pos);
}
virtual void Eval(DenseMatrix &K)
{
Vector pos(3);
for (int i=0; i<K.Size(); i++) {pos(i)=K(i,i);}
(this)->Eval(K,pos);
}
virtual void Eval(DenseMatrix &K, Vector pos)
{
if (typemod == 0)
{
K(0, 0) = 1.0 + 3.0 * std::sin(M_PI*pos(0));
K(0, 1) = 0.0;
K(1, 0) = 0.0;
K(1, 1) = 1.0;
}
else if (typemod==1) //size only circle
{
const double small = 0.001, big = 0.01;
const double xc = pos(0) - 0.5, yc = pos(1) - 0.5;
const double r = sqrt(xc*xc + yc*yc);
double r1 = 0.15; double r2 = 0.35; double sf=30.0;
const double eps = 0.5;
const double tan1 = std::tanh(sf*(r-r1)),
tan2 = std::tanh(sf*(r-r2));
double ind = (tan1 - tan2);
if (ind > 1.0) {ind = 1.;}
if (ind < 0.0) {ind = 0.;}
double val = ind * small + (1.0 - ind) * big;
//K(0, 0) = eps + 1.0 * (tan1 - tan2);
K(0, 0) = 1.0;
K(0, 1) = 0.0;
K(1, 0) = 0.0;
K(1, 1) = 1.0;
K(0,0) *= pow(val,0.5);
K(1,1) *= pow(val,0.5);
}
else if (typemod==2) // size only sine wave
{
const double small = 0.001, big = 0.01;
const double X = pos(0), Y = pos(1);
double ind = std::tanh((10*(Y-0.5) + std::sin(4.0*M_PI*X)) + 1) -
std::tanh((10*(Y-0.5) + std::sin(4.0*M_PI*X)) - 1);
if (ind > 1.0) {ind = 1.;}
if (ind < 0.0) {ind = 0.;}
double val = ind * small + (1.0 - ind) * big;
K(0, 0) = pow(val,0.5);
K(0, 1) = 0.0;
K(1, 0) = 0.0;
K(1, 1) = pow(val,0.5);
}
else if (typemod==3) //circle with size and AR
{
const double small = 0.001, big = 0.01;
const double xc = pos(0)-0.5, yc = pos(1)-0.5;
const double rv = xc*xc + yc*yc;
double r = 0;
if (rv>0.) {r = sqrt(rv);}
double r1 = 0.25; double r2 = 0.30; double sf=30.0;
const double szfac = 1;
const double asfac = 40;
const double eps2 = szfac/asfac;
const double eps1 = szfac;
double tan1 = std::tanh(sf*(r-r1)+1),
tan2 = std::tanh(sf*(r-r2)-1);
double wgt = 0.5*(tan1-tan2);
tan1 = std::tanh(sf*(r-r1)),
tan2 = std::tanh(sf*(r-r2));
double ind = (tan1 - tan2);
if (ind > 1.0) {ind = 1.;}
if (ind < 0.0) {ind = 0.;}
double szval = ind * small + (1.0 - ind) * big;
double th = std::atan2(yc,xc)*180./M_PI;
if (wgt > 1) { wgt = 1; }
if (wgt < 0) { wgt = 0; }
double maxval = eps2 + eps1*(1-wgt)*(1-wgt);
double minval = eps1;
double avgval = 0.5*(maxval+minval);
double ampval = 0.5*(maxval-minval);
double val1 = avgval + ampval*sin(2.*th*M_PI/180.+90*M_PI/180.);
double val2 = avgval + ampval*sin(2.*th*M_PI/180.-90*M_PI/180.);
K(0,1) = 0.0;
K(1,0) = 0.0;
K(0,0) = val1;
K(1,1) = val2;
K(0,0) *= pow(szval,0.5);
K(1,1) *= pow(szval,0.5);
}
else if (typemod == 4) //sharp sine wave
{
const double small = 0.001, big = 0.01;
const double xc = pos(0), yc = pos(1);
const double r = sqrt(xc*xc + yc*yc);
double tfac = 40;
double yl1 = 0.45;
double yl2 = 0.55;
double wgt = std::tanh((tfac*(yc-yl1) + 2*std::sin(4.0*M_PI*xc)) + 1) -
std::tanh((tfac*(yc-yl2) + 2*std::sin(4.0*M_PI*xc)) - 1);
if (wgt > 1) { wgt = 1; }
if (wgt < 0) { wgt = 0; }
double szval = wgt * small + (1.0 - wgt) * big;
const double eps2 = 20;
const double eps1 = 1;
K(1,1) = eps1/eps2 + eps1*(1-wgt)*(1-wgt);
K(0,0) = eps1;
K(0,1) = 0.0;
K(1,0) = 0.0;
//K(0,0) *= pow(szval,0.5);
//K(1,1) *= pow(szval,0.5);
}
else if (typemod == 5) //sharp rotated sine wave
{
double xc = pos(0)-0.5, yc = pos(1)-0.5;
double th = 15.5*M_PI/180.;
double xn = cos(th)*xc + sin(th)*yc;
double yn = -sin(th)*xc + cos(th)*yc;
double th2 = (th > 45.*M_PI/180) ? M_PI/2 - th : th;
double stretch = 1/cos(th2);
xc = xn/stretch;
yc = yn;
double tfac = 20;
double s1 = 3;
double s2 = 2;
double yl1 = -0.025;
double yl2 = 0.025;
double wgt = std::tanh((tfac*(yc-yl1) + s2*std::sin(s1*M_PI*xc)) + 1) -
std::tanh((tfac*(yc-yl2) + s2*std::sin(s1*M_PI*xc)) - 1);
if (wgt > 1) { wgt = 1; }
if (wgt < 0) { wgt = 0; }
const double eps2 = 20;
const double eps1 = 1;
K(1,1) = eps1/eps2 + eps1*(1-wgt)*(1-wgt);
K(0,0) = eps1;
K(0,1) = 0.0;
K(1,0) = 0.0;
}
else if (typemod == 6) //BOUNDARY LAYER REFINEMENT
{
const double szfac = 1;
const double asfac = 500;
const double eps = szfac;
const double eps2 = szfac/asfac;
double yscale = 1.5;
yscale = 2 - 2/asfac;
double yval = 0.25;
K(0, 0) = eps;
K(1, 1) = eps2 + szfac*yscale*pos(1);
K(0, 1) = 0.0;
K(1, 0) = 0.0;
}
}
};
double GetTargetSum(Mesh &mesh, GridFunction &size)
{
L2_FECollection avg_fec(0, mesh.Dimension());
FiniteElementSpace avg_fes(&mesh, &avg_fec);
GridFunction elsize_avgs(&avg_fes);
size.GetElementAverages(elsize_avgs);
return elsize_avgs.Sum();
}
class TMOPEstimator : public ErrorEstimator
{
protected:
long current_sequence;
double total_error;
Array<int> aniso_flags;
FiniteElementSpace *fespace;
MatrixCoefficient *target_spec;
GridFunction *size, tarsize;
GridFunction *aspr, taraspr;
bool discrete_field_flag;
Vector SizeErr, AspErr;
/// Check if the mesh of the solution was modified.
bool MeshIsModified()
{
long mesh_sequence = size->FESpace()->GetMesh()->GetSequence();
MFEM_ASSERT(mesh_sequence >= current_sequence, "");
return (mesh_sequence > current_sequence);
}
/// Compute the element error estimates.
void ComputeEstimates();
public:
TMOPEstimator(FiniteElementSpace &fes,
GridFunction &_size,
GridFunction &_aspr)
: current_sequence(-1),
total_error(0.),
fespace(&fes),
size(&_size),
aspr(&_aspr),
tarsize(),
discrete_field_flag(true) {}
/// Return the total error from the last error estimate.
double GetTotalError() const { return total_error; }
void SetAnalyticTargetSpec(MatrixCoefficient *mspec)
{target_spec = mspec; discrete_field_flag=false;}
virtual const Vector &GetLocalErrors() { return SizeErr; }
virtual const GridFunction &GetLocalSolution() { return tarsize; }
virtual const Vector &GetSizeError()
{
if (MeshIsModified()) { ComputeEstimates(); }
return SizeErr;
}
virtual const Vector &GetAsprError()
{
if (MeshIsModified()) { ComputeEstimates(); }
return AspErr;
}
virtual void Reset() { current_sequence = -1; }
virtual ~TMOPEstimator() {}
};
void TMOPEstimator::ComputeEstimates()
{
// Compute error for each element
Vector size_sol;
Vector aspr_sol;
const int NE = fespace->GetNE(),
dim = fespace->GetMesh()->Dimension();
GridFunction *nodes = fespace->GetMesh()->GetNodes();
Vector nodesv(nodes->GetData(), nodes->Size());
const int pnt_cnt = nodesv.Size()/dim;
if (!discrete_field_flag)
{
DenseMatrix K; K.SetSize(dim);
size_sol.SetSize(pnt_cnt);
aspr_sol.SetSize(pnt_cnt);
HessianCoefficient *target_spec_mod = dynamic_cast<HessianCoefficient *>
(target_spec);
for (int i = 0; i < pnt_cnt; i++)
{
for (int j = 0; j < dim; j++) { K(j,j) = nodesv(i+j*pnt_cnt); }
target_spec_mod->Eval(K);
Vector col1, col2;
K.GetColumn(0, col1);
K.GetColumn(1, col2);
size_sol(i) = K.Det();
aspr_sol(i) = col2.Norml2()/col1.Norml2(); // l2/l1 in 2D
}
size->SetDataAndSize(size_sol.GetData(),size_sol.Size());
aspr->SetDataAndSize(aspr_sol.GetData(),aspr_sol.Size());
}
MFEM_ASSERT(size->Min() > 0,"Target element size should be greater than 0");
MFEM_ASSERT(aspr->Min() > 0,
"Target element aspect-ratio should be greater than 0");
L2_FECollection avg_fec(0, fespace->GetMesh()->Dimension());
FiniteElementSpace avg_fes(fespace->GetMesh(), &avg_fec);
// Target and current Size
tarsize.SetSpace(&avg_fes);
size->GetElementAverages(tarsize);
SizeErr.SetSize(NE);
for (int i = 0; i < NE; i++)
{
double curr_size = fespace->GetMesh()->GetElementVolume(i);
double tar_size = tarsize(i);
SizeErr(i) = curr_size/tar_size;
}
// Target AspectRatio
taraspr.SetSpace(&avg_fes);
AspErr.SetSize(NE);
Vector pos0V(fespace->GetFE(0)->GetDof());
Array<int> pos_dofs;
for (int i = 0; i < NE; i++)
{
aspr->FESpace()->GetElementDofs(i, pos_dofs);
aspr->GetSubVector(pos_dofs, pos0V);
double prod = 1.;
for (int j = 0; j < pos0V.Size(); j++)
{
prod *= pos0V(j);
}
taraspr(i) = pow(prod,1./pos0V.Size());
}
// Current AspectRatio
Vector curr_aspr_vec(NE);
const FiniteElement *fe;
fe = fespace->GetFE(0);
const IntegrationRule *ir = NULL;
if (!ir)
{
ir = &(IntRules.Get(fe->GetGeomType(), 2*fe->GetOrder() + 3)); // <---
}
int dof = fe->GetDof();
DenseMatrix Dsh, Jpr, PMatI;
Dsh.SetSize(dof, dim), PMatI.SetSize(dof, dim), Jpr.SetSize(dim);
Array<int> vdofs;
for (int i = 0; i < NE; i++)
{
fe = fespace->GetFE(i);
fespace->GetElementVDofs(i, vdofs);
for (int j = 0; j < dof; j++)
{
int nodidx = vdofs[j];
for (int k = 0; k < dim; k++)
{
PMatI(j,k) = nodesv(nodidx+k*pnt_cnt);
}
}
double prod = 1;
for (int j = 0; j < ir->GetNPoints(); j++)
{
const IntegrationPoint &ip = ir->IntPoint(j);
fe->CalcDShape(ip, Dsh);
MultAtB(PMatI, Dsh, Jpr);
Vector col1, col2;
Jpr.GetColumn(0, col1);
Jpr.GetColumn(1, col2);
prod *= col2.Norml2()/col1.Norml2();
}
prod = pow(prod,1./ir->GetNPoints());
curr_aspr_vec(i) = prod;
}
for (int i = 0; i < NE; i++)
{
//double curr_aspr = fespace->GetMesh()->GetElementAspectRatio(i, 0);
double curr_aspr = curr_aspr_vec(i);
double tar_aspr = taraspr(i);
AspErr(i) = curr_aspr/tar_aspr;
}
current_sequence = size->FESpace()->GetMesh()->GetSequence();
}
class TMOPRefiner : public MeshOperator
{
protected:
TMOPEstimator &estimator;
long max_elements;
long num_marked_elements;
Array<Refinement> marked_elements;
long current_sequence;
int non_conforming;
int nc_limit;
int amrmetric; //0-Size, 1-AspectRatio, 2-Size+AspectRatio
int dim;
double GetNorm(const Vector &local_err, Mesh &mesh) const;
/** @brief Apply the operator to the mesh.
@return STOP if a stopping criterion is satisfied or no elements were
marked for refinement; REFINED + CONTINUE otherwise. */
virtual int ApplyImpl(Mesh &mesh);
public:
/// Construct a ThresholdRefiner using the given ErrorEstimator.
TMOPRefiner(TMOPEstimator &est, int amrmetric_, int dim_);
// default destructor (virtual)
/// Use nonconforming refinement, if possible (triangles, quads, hexes).
void PreferNonconformingRefinement() { non_conforming = 1; }
/** @brief Use conforming refinement, if possible (triangles, tetrahedra)
-- this is the default. */
void PreferConformingRefinement() { non_conforming = -1; }
/** @brief Set the maximum ratio of refinement levels of adjacent elements
(0 = unlimited). */
void SetNCLimit(int nc_limit)
{
MFEM_ASSERT(nc_limit >= 0, "Invalid NC limit");
this->nc_limit = nc_limit;
}
/// Get the number of marked elements in the last Apply() call.
long GetNumMarkedElements() const { return num_marked_elements; }
/// Reset the associated estimator.
virtual void Reset();
};
TMOPRefiner::TMOPRefiner(TMOPEstimator &est, int amrmetric_, int dim_)
: estimator(est), amrmetric(amrmetric_), dim(dim_)
{
max_elements = std::numeric_limits<long>::max();
num_marked_elements = 0L;
current_sequence = -1;
non_conforming = -1;
nc_limit = 0;
}
int TMOPRefiner::ApplyImpl(Mesh &mesh)
{
num_marked_elements = 0;
marked_elements.SetSize(0);
current_sequence = mesh.GetSequence();
const long num_elements = mesh.GetGlobalNE();
if (num_elements >= max_elements) { return STOP; }
const int NE = mesh.GetNE();
Vector SizeErr = estimator.GetSizeError();
Vector AspErr = estimator.GetAsprError();
MFEM_ASSERT(SizeErr.Size() == NE, "invalid size of local_err");
int inum=0;
for (int el = 0; el < NE; el++)
{
if (dim == 2)
{
if ( ( amrmetric == 1 ) || ( amrmetric == 2 && SizeErr(el) > 4./3))
{
if (AspErr(el) < 2./3)
{
marked_elements.Append(Refinement(el));
marked_elements[inum].ref_type = 1;
inum += 1;
}
else if (AspErr(el) > 4./3)
{
marked_elements.Append(Refinement(el));
marked_elements[inum].ref_type = 2;
inum += 1;
}
}
else if ( ( amrmetric == 0 || amrmetric == 2 ) && SizeErr(el) > 8./5)
{
marked_elements.Append(Refinement(el));
marked_elements[inum].ref_type = 3;
inum += 1;
}
}
else
{
MFEM_ABORT(" dim=3 not implement yet");
}
}
num_marked_elements = mesh.ReduceInt(marked_elements.Size());
if (num_marked_elements == 0) { return STOP; }
mesh.GeneralRefinement(marked_elements, non_conforming, nc_limit);
return CONTINUE + REFINED;
}
void TMOPRefiner::Reset()
{
estimator.Reset();
current_sequence = -1;
num_marked_elements = 0;
}
double weight_fun(const Vector &x);
double ind_values(const Vector &x)
{
const int opt = 2;
const double small = 0.001, big = 0.01;
// Sine wave.
if (opt==1)
{
const double X = x(0), Y = x(1);
double ind = std::tanh((10*(Y-0.5) + std::sin(4.0*M_PI*X)) + 1) -
std::tanh((10*(Y-0.5) + std::sin(4.0*M_PI*X)) - 1);
if (ind > 1.0) {ind = 1.;}
if (ind < 0.0) {ind = 0.;}
return ind * small + (1.0 - ind) * big;
}
if (opt==2)
{
// Circle in the middle.
double val = 0.;
const double xc = x(0) - 0.5, yc = x(1) - 0.5;
const double r = sqrt(xc*xc + yc*yc);
double r1 = 0.15; double r2 = 0.35; double sf=30.0;
val = 0.5*(std::tanh(sf*(r-r1)) - std::tanh(sf*(r-r2)));
if (val > 1.) {val = 1;}
return val * small + (1.0 - val) * big;
}
if (opt == 3)
{
// cross
const double X = x(0), Y = x(1);
const double r1 = 0.45, r2 = 0.55;
const double sf = 40.0;
double val = 0.5 * ( std::tanh(sf*(X-r1)) - std::tanh(sf*(X-r2)) +
std::tanh(sf*(Y-r1)) - std::tanh(sf*(Y-r2)) );
if (val > 1.) { val = 1.0; }
return val * small + (1.0 - val) * big;
}
if (opt==4)
{
// Multiple circles
double r1,r2,val,rval;
double sf = 10;
val = 0.;
// circle 1
r1= 0.25; r2 = 0.25; rval = 0.1;
double xc = x(0) - r1, yc = x(1) - r2;
double r = sqrt(xc*xc+yc*yc);
val = 0.5*(1+std::tanh(sf*(r+rval))) - 0.5*(1+std::tanh(sf*
(r-rval)));// std::exp(val1);
// circle 2
r1= 0.75; r2 = 0.75;
xc = x(0) - r1, yc = x(1) - r2;
r = sqrt(xc*xc+yc*yc);
val += (0.5*(1+std::tanh(sf*(r+rval))) - 0.5*(1+std::tanh(sf*
(r-rval))));// std::exp(val1);
// circle 3
r1= 0.75; r2 = 0.25;
xc = x(0) - r1, yc = x(1) - r2;
r = sqrt(xc*xc+yc*yc);
val += 0.5*(1+std::tanh(sf*(r+rval))) - 0.5*(1+std::tanh(sf*
(r-rval)));// std::exp(val1);
// circle 4
r1= 0.25; r2 = 0.75;
xc = x(0) - r1, yc = x(1) - r2;
r = sqrt(xc*xc+yc*yc);
val += 0.5*(1+std::tanh(sf*(r+rval))) - 0.5*(1+std::tanh(sf*(r-rval)));
if (val > 1.0) {val = 1.;}
if (val < 0.0) {val = 0.;}
return val * small + (1.0 - val) * big;
}
if (opt==5)
{
// cross
double val = 0.;
double X = x(0)-0.5, Y = x(1)-0.5;
double rval = std::sqrt(X*X + Y*Y);
double thval = 60.*M_PI/180.;
double Xmod,Ymod;
Xmod = X*std::cos(thval) + Y*std::sin(thval);
Ymod= -X*std::sin(thval) + Y*std::cos(thval);
X = Xmod+0.5; Y = Ymod+0.5;
double r1 = 0.45; double r2 = 0.55; double sf=30.0;
val = ( 0.5*(1+std::tanh(sf*(X-r1))) - 0.5*(1+std::tanh(sf*(X-r2)))
+ 0.5*(1+std::tanh(sf*(Y-r1))) - 0.5*(1+std::tanh(sf*(Y-r2))) );
if (rval > 0.4) {val = 0.;}
if (val > 1.0) {val = 1.;}
if (val < 0.0) {val = 0.;}
return val * small + (1.0 - val) * big;
}
if (opt==6)
{
double val = 0.;
const double xc = x(0) - 0.0, yc = x(1) - 0.5;
const double r = sqrt(xc*xc + yc*yc);
double r1 = 0.45; double r2 = 0.55; double sf=30.0;
val = 0.5*(1+std::tanh(sf*(r-r1))) - 0.5*(1+std::tanh(sf*(r-r2)));
if (val > 1.) {val = 1;}
if (val < 0.) {val = 0;}
return val * small + (1.0 - val) * big;
}
return 0.0;
}
void TMOPupdate(NonlinearForm &a, Mesh &mesh, FiniteElementSpace &fespace,
bool move_bnd)
{
int dim = fespace.GetFE(0)->GetDim();
if (move_bnd == false)
{
Array<int> ess_bdr(mesh.bdr_attributes.Max());
ess_bdr = 1;
a.SetEssentialBC(ess_bdr);
}
else
{
const int nd = fespace.GetBE(0)->GetDof();
int n = 0;
for (int i = 0; i < mesh.GetNBE(); i++)
{
const int attr = mesh.GetBdrElement(i)->GetAttribute();
MFEM_VERIFY(!(dim == 2 && attr == 3),
"Boundary attribute 3 must be used only for 3D meshes. "
"Adjust the attributes (1/2/3/4 for fixed x/y/z/all "
"components, rest for free nodes), or use -fix-bnd.");
if (attr == 1 || attr == 2 || attr == 3) { n += nd; }
if (attr == 4) { n += nd * dim; }
}
Array<int> ess_vdofs(n), vdofs;
n = 0;
for (int i = 0; i < mesh.GetNBE(); i++)
{
const int attr = mesh.GetBdrElement(i)->GetAttribute();
fespace.GetBdrElementVDofs(i, vdofs);
if (attr == 1) // Fix x components.
{
for (int j = 0; j < nd; j++)
{ ess_vdofs[n++] = vdofs[j]; }
}
else if (attr == 2) // Fix y components.
{
for (int j = 0; j < nd; j++)
{ ess_vdofs[n++] = vdofs[j+nd]; }
}
else if (attr == 3) // Fix z components.
{
for (int j = 0; j < nd; j++)
{ ess_vdofs[n++] = vdofs[j+2*nd]; }
}
else if (attr == 4) // Fix all components.
{
for (int j = 0; j < vdofs.Size(); j++)
{ ess_vdofs[n++] = vdofs[j]; }
}
}
a.SetEssentialVDofs(ess_vdofs);
}
};
// Additional IntegrationRules that can be used with the --quad-type option.
IntegrationRules IntRulesLo(0, Quadrature1D::GaussLobatto);
IntegrationRules IntRulesCU(0, Quadrature1D::ClosedUniform);
int main (int argc, char *argv[])
{
// 0. Set the method's default parameters.
const char *mesh_file = "icf.mesh";
int mesh_poly_deg = 1;
int rs_levels = 0;
double jitter = 0.0;
int metric_id = 1;
int target_id = 1;
double lim_const = 0.0;
int quad_type = 1;
int quad_order = 8;
int newton_iter = 10;
double newton_rtol = 1e-12;
int lin_solver = 2;
int max_lin_iter = 100;
bool move_bnd = true;
bool combomet = 0;
int amr_flag = 1;
int amrmetric = 2;
bool normalization = false;
bool visualization = true;
int verbosity_level = 0;
int hessiantype = 1;
// 1. Parse command-line options.
OptionsParser args(argc, argv);
args.AddOption(&mesh_file, "-m", "--mesh",
"Mesh file to use.");
args.AddOption(&mesh_poly_deg, "-o", "--order",
"Polynomial degree of mesh finite element space.");
args.AddOption(&rs_levels, "-rs", "--refine-serial",
"Number of times to refine the mesh uniformly in serial.");
args.AddOption(&jitter, "-ji", "--jitter",
"Random perturbation scaling factor.");
args.AddOption(&metric_id, "-mid", "--metric-id",
"Mesh optimization metric:\n\t"
"1 : |T|^2 -- 2D shape\n\t"
"2 : 0.5|T|^2/tau-1 -- 2D shape (condition number)\n\t"
"7 : |T-T^-t|^2 -- 2D shape+size\n\t"
"9 : tau*|T-T^-t|^2 -- 2D shape+size\n\t"
"22 : 0.5(|T|^2-2*tau)/(tau-tau_0) -- 2D untangling\n\t"
"50 : 0.5|T^tT|^2/tau^2-1 -- 2D shape\n\t"
"55 : (tau-1)^2 -- 2D size\n\t"
"56 : 0.5(sqrt(tau)-1/sqrt(tau))^2 -- 2D size\n\t"
"58 : |T^tT|^2/(tau^2)-2*|T|^2/tau+2 -- 2D shape\n\t"
"77 : 0.5(tau-1/tau)^2 -- 2D size\n\t"
"211: (tau-1)^2-tau+sqrt(tau^2) -- 2D untangling\n\t"
"252: 0.5(tau-1)^2/(tau-tau_0) -- 2D untangling\n\t"
"301: (|T||T^-1|)/3-1 -- 3D shape\n\t"
"302: (|T|^2|T^-1|^2)/9-1 -- 3D shape\n\t"
"303: (|T|^2)/3*tau^(2/3)-1 -- 3D shape\n\t"
"315: (tau-1)^2 -- 3D size\n\t"
"316: 0.5(sqrt(tau)-1/sqrt(tau))^2 -- 3D size\n\t"
"321: |T-T^-t|^2 -- 3D shape+size\n\t"
"352: 0.5(tau-1)^2/(tau-tau_0) -- 3D untangling");
args.AddOption(&target_id, "-tid", "--target-id",
"Target (ideal element) type:\n\t"
"1: Ideal shape, unit size\n\t"
"2: Ideal shape, equal size\n\t"
"3: Ideal shape, initial size\n\t"
"4: Given full analytic Jacobian (in physical space)\n\t"
"5: Ideal shape, given size (in physical space)");
args.AddOption(&lim_const, "-lc", "--limit-const", "Limiting constant.");
args.AddOption(&quad_type, "-qt", "--quad-type",
"Quadrature rule type:\n\t"
"1: Gauss-Lobatto\n\t"
"2: Gauss-Legendre\n\t"
"3: Closed uniform points");
args.AddOption(&quad_order, "-qo", "--quad_order",
"Order of the quadrature rule.");
args.AddOption(&newton_iter, "-ni", "--newton-iters",
"Maximum number of Newton iterations.");
args.AddOption(&newton_rtol, "-rtol", "--newton-rel-tolerance",
"Relative tolerance for the Newton solver.");
args.AddOption(&lin_solver, "-ls", "--lin-solver",
"Linear solver: 0 - l1-Jacobi, 1 - CG, 2 - MINRES.");
args.AddOption(&max_lin_iter, "-li", "--lin-iter",
"Maximum number of iterations in the linear solve.");
args.AddOption(&move_bnd, "-bnd", "--move-boundary", "-fix-bnd",
"--fix-boundary",
"Enable motion along horizontal and vertical boundaries.");
args.AddOption(&combomet, "-cmb", "--combo-met", "-no-cmb", "--no-combo-met",
"Combination of metrics.");
args.AddOption(&amr_flag, "-amr", "--amr-flag",
"1 - AMR after TMOP");
args.AddOption(&amrmetric, "-amrm", "--amr-metric",
"0 - Size, 1 - AspectRatio, 2 - Size + AspectRatio");
args.AddOption(&hessiantype, "-ht", "--Hessian Target type",
"1-6");
args.AddOption(&normalization, "-nor", "--normalization", "-no-nor",
"--no-normalization",
"Make all terms in the optimization functional unitless.");
args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
"--no-visualization",
"Enable or disable GLVis visualization.");
args.AddOption(&verbosity_level, "-vl", "--verbosity-level",
"Set the verbosity level - 0, 1, or 2.");
args.Parse();
if (!args.Good())
{
args.PrintUsage(cout);
return 1;
}
args.PrintOptions(cout);
// 2. Initialize and refine the starting mesh.
Mesh mesh(mesh_file, 1, 1, false);
for (int lev = 0; lev < rs_levels; lev++) { mesh.UniformRefinement(); }
const int dim = mesh.Dimension();
cout << "Mesh curvature: ";
if (mesh.GetNodes()) { cout << mesh.GetNodes()->OwnFEC()->Name(); }
else { cout << "(NONE)"; }
cout << endl;
// 3. Define a finite element space on the mesh. Here we use vector finite
// elements which are tensor products of quadratic finite elements. The
// number of components in the vector finite element space is specified by
// the last parameter of the FiniteElementSpace constructor.
H1_FECollection fec(mesh_poly_deg, dim);
FiniteElementSpace fespace(&mesh, &fec, dim);
// 4. Make the mesh curved based on the above finite element space. This
// means that we define the mesh elements through a fespace-based
// transformation of the reference element.
mesh.SetNodalFESpace(&fespace);
// 5. Set up an empty right-hand side vector b, which is equivalent to b=0.
Vector b(0);
// 6. Get the mesh nodes (vertices and other degrees of freedom in the finite
// element space) as a finite element grid function in fespace. Note that
// changing x automatically changes the shapes of the mesh elements.
GridFunction x(&fespace);
GridFunction xnew(&fespace);
GridFunction x0new(&fespace);
mesh.SetNodalGridFunction(&x);
// 7. Define a vector representing the minimal local mesh size in the mesh
// nodes. We index the nodes using the scalar version of the degrees of
// freedom in pfespace. Note: this is partition-dependent.
//
// In addition, compute average mesh size and total volume.
Vector h0(fespace.GetNDofs());
h0 = infinity();
double volume = 0.0;
Array<int> dofs;
for (int i = 0; i < mesh.GetNE(); i++)
{
// Get the local scalar element degrees of freedom in dofs.
fespace.GetElementDofs(i, dofs);
// Adjust the value of h0 in dofs based on the local mesh size.
const double hi = mesh.GetElementSize(i);
for (int j = 0; j < dofs.Size(); j++)
{
h0(dofs[j]) = min(h0(dofs[j]), hi);
}
volume += mesh.GetElementVolume(i);
}
const double small_phys_size = pow(volume, 1.0 / dim) / 100.0;
// 8. Add a random perturbation to the nodes in the interior of the domain.
// We define a random grid function of fespace and make sure that it is
// zero on the boundary and its values are locally of the order of h0.
// The latter is based on the DofToVDof() method which maps the scalar to
// the vector degrees of freedom in fespace.
GridFunction rdm(&fespace);
rdm.Randomize();
rdm -= 0.25; // Shift to random values in [-0.5,0.5].
rdm *= jitter;
// Scale the random values to be of order of the local mesh size.
for (int i = 0; i < fespace.GetNDofs(); i++)
{
for (int d = 0; d < dim; d++)
{
rdm(fespace.DofToVDof(i,d)) *= h0(i);
}
}
Array<int> vdofs;
for (int i = 0; i < fespace.GetNBE(); i++)
{
// Get the vector degrees of freedom in the boundary element.
fespace.GetBdrElementVDofs(i, vdofs);
// Set the boundary values to zero.
for (int j = 0; j < vdofs.Size(); j++) { rdm(vdofs[j]) = 0.0; }
}
x -= rdm;
x.SetTrueVector();
x.SetFromTrueVector();
// 9. Save the starting (prior to the optimization) mesh to a file. This
// output can be viewed later using GLVis: "glvis -m perturbed.mesh".
{
ofstream mesh_ofs("perturbed.mesh");
mesh.Print(mesh_ofs);
}
// 10. Store the starting (prior to the optimization) positions.
GridFunction x0(&fespace);
x0 = x;
// 11. Form the integrator that uses the chosen metric and target.
double tauval = -0.1;
TMOP_QualityMetric *metric = NULL;
switch (metric_id)
{
case 1: metric = new TMOP_Metric_001; break;
case 2: metric = new TMOP_Metric_002; break;
case 7: metric = new TMOP_Metric_007; break;
case 9: metric = new TMOP_Metric_009; break;
case 22: metric = new TMOP_Metric_022(tauval); break;
case 50: metric = new TMOP_Metric_050; break;
case 55: metric = new TMOP_Metric_055; break;
case 56: metric = new TMOP_Metric_056; break;
case 58: metric = new TMOP_Metric_058; break;
case 77: metric = new TMOP_Metric_077; break;
case 211: metric = new TMOP_Metric_211; break;
case 252: metric = new TMOP_Metric_252(tauval); break;
case 301: metric = new TMOP_Metric_301; break;
case 302: metric = new TMOP_Metric_302; break;
case 303: metric = new TMOP_Metric_303; break;
case 315: metric = new TMOP_Metric_315; break;
case 316: metric = new TMOP_Metric_316; break;
case 321: metric = new TMOP_Metric_321; break;
case 352: metric = new TMOP_Metric_352(tauval); break;
default: cout << "Unknown metric_id: " << metric_id << endl; return 3;
}
TargetConstructor::TargetType target_t;
TargetConstructor *target_c = NULL;
HessianCoefficient *adapt_coeff = NULL;
H1_FECollection ind_fec(mesh_poly_deg, dim);
FiniteElementSpace ind_fes(&mesh, &ind_fec);
GridFunction size; size.SetSpace(&ind_fes);
GridFunction aspr; aspr.SetSpace(&ind_fes);
DiscreteAdaptTC *tcd = NULL;
AnalyticAdaptTC *tca = NULL;
switch (target_id)
{
case 1: target_t = TargetConstructor::IDEAL_SHAPE_UNIT_SIZE; break;
case 2: target_t = TargetConstructor::IDEAL_SHAPE_EQUAL_SIZE; break;
case 3: target_t = TargetConstructor::IDEAL_SHAPE_GIVEN_SIZE; break;
case 4:
{
target_t = TargetConstructor::GIVEN_FULL;
tca = new AnalyticAdaptTC(target_t);
adapt_coeff = new HessianCoefficient(dim, hessiantype);
tca->SetAnalyticTargetSpec(NULL, NULL, adapt_coeff);
target_c = tca;
break;
}
case 5:
{
target_t = TargetConstructor::IDEAL_SHAPE_GIVEN_SIZE;
tcd = new DiscreteAdaptTC(target_t);
size.SetSpace(&ind_fes);
FunctionCoefficient ind_coeff(ind_values);
size.ProjectCoefficient(ind_coeff);
tcd->SetSerialDiscreteTargetSpec(size);
target_c = tcd;
break;
}
default: cout << "Unknown target_id: " << target_id << endl; return 3;
}
if (target_c == NULL)
{
target_c = new TargetConstructor(target_t);
}
target_c->SetNodes(x0);
TMOP_Integrator *he_nlf_integ = new TMOP_Integrator(metric, target_c);
// 12. Setup the quadrature rule for the non-linear form integrator.
const IntegrationRule *ir = NULL;
const int geom_type = fespace.GetFE(0)->GetGeomType();
switch (quad_type)
{
case 1: ir = &IntRulesLo.Get(geom_type, quad_order); break;
case 2: ir = &IntRules.Get(geom_type, quad_order); break;
case 3: ir = &IntRulesCU.Get(geom_type, quad_order); break;
default: cout << "Unknown quad_type: " << quad_type << endl;
delete he_nlf_integ; return 3;
}
cout << "Quadrature points per cell: " << ir->GetNPoints() << endl;
he_nlf_integ->SetIntegrationRule(*ir);
if (normalization) { he_nlf_integ->EnableNormalization(x0); }
// 13. Limit the node movement.
// The limiting distances can be given by a general function of space.
GridFunction dist(&fespace);
dist = 1.0;
// The small_phys_size is relevant only with proper normalization.
if (normalization) { dist = small_phys_size; }
ConstantCoefficient lim_coeff(lim_const);
if (lim_const != 0.0) { he_nlf_integ->EnableLimiting(x0, dist, lim_coeff); }
// 14. Setup the final NonlinearForm (which defines the integral of interest,
// its first and second derivatives). Here we can use a combination of
// metrics, i.e., optimize the sum of two integrals, where both are
// scaled by used-defined space-dependent weights. Note that there are no
// command-line options for the weights and the type of the second
// metric; one should update those in the code.
NonlinearForm a(&fespace);
ConstantCoefficient *coeff1 = NULL;
TMOP_QualityMetric *metric2 = NULL;
TargetConstructor *target_c2 = NULL;
FunctionCoefficient coeff2(weight_fun);
if (combomet == 1)
{
// TODO normalization of combinations.
// We will probably drop this example and replace it with adaptivity.
if (normalization) { MFEM_ABORT("Not implemented."); }
// Weight of the original metric.
coeff1 = new ConstantCoefficient(1.0);
he_nlf_integ->SetCoefficient(*coeff1);
a.AddDomainIntegrator(he_nlf_integ);
metric2 = new TMOP_Metric_077;
target_c2 = new TargetConstructor(
TargetConstructor::IDEAL_SHAPE_EQUAL_SIZE);
target_c2->SetVolumeScale(0.01);
target_c2->SetNodes(x0);
TMOP_Integrator *he_nlf_integ2 = new TMOP_Integrator(metric2, target_c2);
he_nlf_integ2->SetIntegrationRule(*ir);
// Weight of metric2.
he_nlf_integ2->SetCoefficient(coeff2);
a.AddDomainIntegrator(he_nlf_integ2);
}
else { a.AddDomainIntegrator(he_nlf_integ); }
const double init_energy = a.GetGridFunctionEnergy(x);
// 15. Visualize the starting mesh and metric values.
if (visualization)
{
char title[] = "Initial metric values";
vis_tmop_metric_s(mesh_poly_deg, *metric, *target_c, mesh, title, 0);
}
// 16. Fix all boundary nodes, or fix only a given component depending on the
// boundary attributes of the given mesh. Attributes 1/2/3 correspond to
// fixed x/y/z components of the node. Attribute 4 corresponds to an
// entirely fixed node. Other boundary attributes do not affect the node
// movement boundary conditions.
if (move_bnd == false)
{
Array<int> ess_bdr(mesh.bdr_attributes.Max());
ess_bdr = 1;
a.SetEssentialBC(ess_bdr);
}
else
{
const int nd = fespace.GetBE(0)->GetDof();
int n = 0;
for (int i = 0; i < mesh.GetNBE(); i++)
{
const int attr = mesh.GetBdrElement(i)->GetAttribute();
MFEM_VERIFY(!(dim == 2 && attr == 3),
"Boundary attribute 3 must be used only for 3D meshes. "
"Adjust the attributes (1/2/3/4 for fixed x/y/z/all "
"components, rest for free nodes), or use -fix-bnd.");
if (attr == 1 || attr == 2 || attr == 3) { n += nd; }
if (attr == 4) { n += nd * dim; }
}
Array<int> ess_vdofs(n), vdofs;
n = 0;
for (int i = 0; i < mesh.GetNBE(); i++)
{
const int attr = mesh.GetBdrElement(i)->GetAttribute();
fespace.GetBdrElementVDofs(i, vdofs);
if (attr == 1) // Fix x components.
{
for (int j = 0; j < nd; j++)
{ ess_vdofs[n++] = vdofs[j]; }
}
else if (attr == 2) // Fix y components.
{
for (int j = 0; j < nd; j++)
{ ess_vdofs[n++] = vdofs[j+nd]; }
}
else if (attr == 3) // Fix z components.
{
for (int j = 0; j < nd; j++)
{ ess_vdofs[n++] = vdofs[j+2*nd]; }
}
else if (attr == 4) // Fix all components.
{
for (int j = 0; j < vdofs.Size(); j++)
{ ess_vdofs[n++] = vdofs[j]; }
}
}
a.SetEssentialVDofs(ess_vdofs);
}
// 17. As we use the Newton method to solve the resulting nonlinear system,
// here we setup the linear solver for the system's Jacobian.
Solver *S = NULL;
const double linsol_rtol = 1e-12;
if (lin_solver == 0)
{
S = new DSmoother(1, 1.0, max_lin_iter);
}
else if (lin_solver == 1)
{
CGSolver *cg = new CGSolver;
cg->SetMaxIter(max_lin_iter);
cg->SetRelTol(linsol_rtol);
cg->SetAbsTol(0.0);
cg->SetPrintLevel(verbosity_level >= 2 ? 3 : -1);
S = cg;
}
else
{
MINRESSolver *minres = new MINRESSolver;
minres->SetMaxIter(max_lin_iter);
minres->SetRelTol(linsol_rtol);
minres->SetAbsTol(0.0);
minres->SetPrintLevel(verbosity_level >= 2 ? 3 : -1);
S = minres;
}
// 18. Compute the minimum det(J) of the starting mesh.
tauval = infinity();
const int NE = mesh.GetNE();
for (int i = 0; i < NE; i++)
{
ElementTransformation *transf = mesh.GetElementTransformation(i);
for (int j = 0; j < ir->GetNPoints(); j++)
{
transf->SetIntPoint(&ir->IntPoint(j));
tauval = min(tauval, transf->Jacobian().Det());
}
}
cout << "Minimum det(J) of the original mesh is " << tauval << endl;
// 19. Finally, perform the nonlinear optimization.
NewtonSolver *newton = NULL;
if (tauval > 0.0)
{
tauval = 0.0;
TMOPNewtonSolver *tns = new TMOPNewtonSolver(*ir);
if (target_id == 5)
{
tns->SetDiscreteAdaptTC(dynamic_cast<DiscreteAdaptTC *>(target_c));
}
newton = tns;
cout << "TMOPNewtonSolver is used (as all det(J) > 0).\n";
}
else
{
if ( (dim == 2 && metric_id != 22 && metric_id != 252) ||
(dim == 3 && metric_id != 352) )
{
cout << "The mesh is inverted. Use an untangling metric." << endl;
return 3;
}
tauval -= 0.01 * h0.Min(); // Slightly below minJ0 to avoid div by 0.
newton = new TMOPDescentNewtonSolver(*ir);
cout << "The TMOPDescentNewtonSolver is used (as some det(J) < 0).\n";
}
newton->SetPreconditioner(*S);
newton->SetMaxIter(newton_iter);
newton->SetRelTol(newton_rtol);
newton->SetAbsTol(0.0);
newton->SetPrintLevel(verbosity_level >= 1 ? 1 : -1);
// 20. AMR based size refinemenet if a size metric is used
TMOPEstimator tmope(ind_fes,size,aspr);
if (target_id==4) {tmope.SetAnalyticTargetSpec(adapt_coeff);}
TMOPRefiner tmopr(tmope, amrmetric, dim);
int newtonstop = 0;
if (amr_flag==1)
{
int ni_limit = 3; //Newton + AMR
int nic_limit = std::max(ni_limit, 4); //Number of iterations with AMR
int amrstop = 0;
int nc_limit = 1; //AMR per iteration - FIXED FOR NOW
tmopr.PreferNonconformingRefinement();
tmopr.SetNCLimit(nc_limit);
for (int it = 0; it<ni_limit; it++)
{
std::cout << it << " Begin NEWTON+AMR Iteration\n";
newton->SetOperator(a);
newton->Mult(b, x.GetTrueVector());
x.SetFromTrueVector();
if (newton->GetConverged() == false)
{
cout << "NewtonIteration: rtol = " << newton_rtol << " not achieved."
<< endl;
}
if (amrstop==1)
{
newtonstop = 1;
cout << it << " Newton and AMR have converged" << endl;
break;
}
char title1[10];
sprintf(title1, "%s %d","Newton", it);
//vis_tmop_metric_s(mesh_poly_deg, *metric, *target_c, mesh, title1, 600);
for (int amrit=0; amrit<nc_limit; amrit++)
{
tmopr.Reset();
if (nc_limit!=0 && amrstop==0) {tmopr.Apply(mesh);}
//Update stuff
ind_fes.Update(); fespace.Update();
size.Update(); aspr.Update();
x.Update(); x.SetTrueVector();
x0.Update(); x0.SetTrueVector();
ind_fes.UpdatesFinished();
fespace.UpdatesFinished();
if (target_id == 5)
{
tcd->SetSerialDiscreteTargetSpec(size);
target_c = tcd;
he_nlf_integ->UpdateTargetConstructor(target_c);
}
a.Update();
TMOPupdate(a,mesh,fespace,move_bnd);
if (amrstop==0)
{
if (tmopr.Stop())
{
amrstop = 1;
cout << it << " " << amrit <<
" AMR stopping criterion satisfied. Stop." << endl;
}
else
{std::cout << mesh.GetNE() << " Number of elements after AMR\n";}
}
}
if (it==nic_limit-1) {amrstop=1;}
//double newabstol = newton->GetNormGoal();
//newton->SetAbsTol(newabstol);
//newton->SetRelTol(0.);
sprintf(title1, "%s %d","AMR", it);
//qqvis_tmop_metric_s(mesh_poly_deg, *metric, *target_c, mesh, title1, 600);
} //ni_limit
} //amr_flag==1
if (newtonstop == 0)
{
newton->SetOperator(a);
newton->Mult(b, x.GetTrueVector());
x.SetFromTrueVector();
}
// 21. Save the optimized mesh to a file. This output can be viewed later
// using GLVis: "glvis -m optimized.mesh".
{
ofstream mesh_ofs("optimized.mesh");
mesh_ofs.precision(14);
mesh.Print(mesh_ofs);
}
string namefile;
char numstr[1]; // enough to hold all numbers up to 64-bits
sprintf(numstr, "%s%d%s", "optimized_ht_", hessiantype, ".mesh");
{
ofstream mesh_ofs(numstr);
mesh_ofs.precision(14);
mesh.Print(mesh_ofs);
}
// 22. Compute the amount of energy decrease.
const double fin_energy = a.GetGridFunctionEnergy(x);
double metric_part = fin_energy;
if (lim_const != 0.0)
{
lim_coeff.constant = 0.0;
metric_part = a.GetGridFunctionEnergy(x);
lim_coeff.constant = lim_const;
}
cout << "Initial strain energy: " << init_energy
<< " = metrics: " << init_energy
<< " + limiting term: " << 0.0 << endl;
cout << " Final strain energy: " << fin_energy
<< " = metrics: " << metric_part
<< " + limiting term: " << fin_energy - metric_part << endl;
cout << "The strain energy decreased by: " << setprecision(12)
<< (init_energy - fin_energy) * 100.0 / init_energy << " %." << endl;
// 22. Visualize the final mesh and metric values.
if (visualization)
{
char title[] = "Final metric values";
vis_tmop_metric_s(mesh_poly_deg, *metric, *target_c, mesh, title, 600);
}
// 23. Visualize the mesh displacement.
if (visualization)
{
osockstream sock(19916, "localhost");
sock << "solution\n";
mesh.Print(sock);
x0 -= x;
x0.Save(sock);
sock.send();
sock << "window_title 'Displacements'\n"
<< "window_geometry "
<< 1200 << " " << 0 << " " << 600 << " " << 600 << "\n"
<< "keys jRmclA" << endl;
}
// 24. Free the used memory.
delete newton;
delete S;
delete target_c2;
delete metric2;
delete coeff1;
delete target_c;
delete metric;
return 0;
}
// Defined with respect to the icf mesh.
double weight_fun(const Vector &x)
{
const double r = sqrt(x(0)*x(0) + x(1)*x(1) + 1e-12);
const double den = 0.002;
double l2 = 0.2 + 0.5*std::tanh((r-0.16)/den) - 0.5*std::tanh((r-0.17)/den)
+ 0.5*std::tanh((r-0.23)/den) - 0.5*std::tanh((r-0.24)/den);
return l2;
}