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mfem/examples/solvers-dev/FOSLS_maxwell.cpp
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// MFEM Example multigrid-grid Cycle
//
// Compile with: make mg_maxwellp
//
// Sample runs: mg_maxwellp -m ../data/one-hex.mesh
#include "mfem.hpp"
#include "as/schwarz.hpp"
#include <fstream>
#include <iostream>
using namespace std;
using namespace mfem;
// Define exact solution
void E_exact(const Vector &x, Vector &E);
void H_exact(const Vector &x, Vector &H);
void scaledf_exact_H(const Vector &x, Vector &f_H);
void f_exact_H(const Vector &x, Vector &f_H);
void get_maxwell_solution(const Vector &x, double E[], double curlE[], double curl2E[]);
int dim;
double omega;
int sol = 1;
int main(int argc, char *argv[])
{
StopWatch chrono;
// 1. Parse command-line options.
// geometry file
// const char *mesh_file = "../data/star.mesh";
const char *mesh_file = "../../data/one-hex.mesh";
// finite element order of approximation
int order = 1;
int sdim = 3;
// static condensation flag
bool static_cond = false;
// visualization flag
bool visualization = 1;
int ref_levels = 1;
int initref = 1;
// number of wavelengths
double k = 0.5;
double theta = 0.5;
double smth_maxit = 1;
// optional command line inputs
OptionsParser args(argc, argv);
args.AddOption(&mesh_file, "-m", "--mesh",
"Mesh file to use.");
args.AddOption(&order, "-o", "--order",
"Finite element order (polynomial degree) or -1 for"
" isoparametric space.");
args.AddOption(&sdim, "-d", "--dimension", "Dimension");
args.AddOption(&ref_levels, "-ref", "--serial-refinements",
"Number of mesh refinements");
args.AddOption(&initref, "-initref", "--init-refinements",
"Number of initial mesh refinements");
args.AddOption(&k, "-k", "--wavelengths",
"Number of wavelengths.");
args.AddOption(&smth_maxit, "-sm", "--smoother-maxit",
"Number of smoothing steps.");
args.AddOption(&theta, "-th", "--theta",
"Dumping parameter for the smoother.");
args.AddOption(&sol, "-sol", "--solution",
"Exact Solution: 0) Polynomial, 1) Sinusoidal.");
args.AddOption(&static_cond, "-sc", "--static-condensation", "-no-sc",
"--no-static-condensation", "Enable static condensation.");
args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
"--no-visualization",
"Enable or disable GLVis visualization.");
args.Parse();
if (!args.Good())
{
args.PrintUsage(cout);
return 1;
}
args.PrintOptions(cout);
// Angular frequency
// omega = k;
// omega = 2.0 * M_PI * k;
omega = 2.0 * M_PI * k;
// 3. Read the mesh from the given mesh file.
// Mesh *mesh = new Mesh(mesh_file, 1, 1);
Mesh *mesh;
// Define a simple square or cubic mesh
mesh = new Mesh(1, 1, 1, Element::HEXAHEDRON, true, 1.0, 1.0, 1.0, false);
dim = mesh->Dimension();
for (int i = 0; i < initref; i++)
{
mesh->UniformRefinement();
}
Mesh *cmesh = new Mesh(*mesh);
for (int l = 0; l < ref_levels; l++)
{
mesh->UniformRefinement();
}
// 4. Define a finite element space on the mesh.
FiniteElementCollection *NDfec = new ND_FECollection(order, dim);
FiniteElementSpace *NDfespace = new FiniteElementSpace(mesh, NDfec);
Array<int> ess_tdof_list;
Array<int> ess_bdr;
if (mesh->bdr_attributes.Size())
{
ess_bdr.SetSize(mesh->bdr_attributes.Max());
ess_bdr = 1;
// Essential BC on E. Nothing on H
NDfespace->GetEssentialTrueDofs(ess_bdr, ess_tdof_list);
}
Array<int> block_offsets(3);
block_offsets[0] = 0;
block_offsets[1] = NDfespace->GetVSize();
block_offsets[2] = NDfespace->GetVSize();
block_offsets.PartialSum();
// _ _ _ _ _ _
// | | | | | |
// | A00 A01 | | E | |F_E |
// | | | | = | |
// | A10 A11 | | H | |F_G |
// |_ _| |_ _| |_ _|
//
// A00 = (curl E, curl F) + \omega^2 (E,F)
// A01 = - \omega *( (curl E, F) + (E,curl F)
// A10 = - \omega *( (curl H, G) + (H,curl G)
// A11 = (curl H, curl H) + \omega^2 (H,G)
BlockVector x(block_offsets), b(block_offsets);
x = 0.0;
b = 0.0;
VectorFunctionCoefficient * Eex = new VectorFunctionCoefficient(dim, E_exact);
GridFunction *E_gf = new GridFunction;
E_gf->MakeRef(NDfespace, x.GetBlock(0));
E_gf->ProjectCoefficient(*Eex);
VectorFunctionCoefficient * Hex;
Hex = new VectorFunctionCoefficient(sdim, H_exact);
GridFunction *H_gf = new GridFunction;
H_gf->MakeRef(NDfespace, x.GetBlock(1));
H_gf->ProjectCoefficient(*Hex);
// 6. Set up the linear form
VectorFunctionCoefficient sf_H(dim, scaledf_exact_H);
VectorFunctionCoefficient f_H(dim, f_exact_H);
LinearForm *b_E = new LinearForm;
b_E->Update(NDfespace, b.GetBlock(0), 0);
b_E->AddDomainIntegrator(new VectorFEDomainLFIntegrator(sf_H));
b_E->Assemble();
LinearForm *b_H = new LinearForm;
b_H->Update(NDfespace, b.GetBlock(1), 0);
b_H->AddDomainIntegrator(new VectorFEDomainLFCurlIntegrator(f_H));
b_H->Assemble();
// 7. Bilinear form a(.,.) on the finite element space
ConstantCoefficient one(1.0);
ConstantCoefficient sigma(pow(omega, 2));
ConstantCoefficient neg(-abs(omega));
ConstantCoefficient pos(abs(omega));
//
BilinearForm *a_EE = new BilinearForm(NDfespace);
a_EE->AddDomainIntegrator(new CurlCurlIntegrator(one));
a_EE->AddDomainIntegrator(new VectorFEMassIntegrator(sigma));
a_EE->Assemble();
a_EE->EliminateEssentialBC(ess_bdr, x.GetBlock(0), b.GetBlock(0));
a_EE->Finalize();
SparseMatrix &A_EE = a_EE->SpMat();
MixedBilinearForm *a_EH = new MixedBilinearForm(NDfespace, NDfespace);
a_EH->AddDomainIntegrator(new MixedVectorCurlIntegrator(neg));
a_EH->AddDomainIntegrator(new MixedVectorWeakCurlIntegrator(neg));
a_EH->Assemble();
a_EH->EliminateTrialDofs(ess_bdr, x.GetBlock(0), b.GetBlock(1));
a_EH->Finalize();
SparseMatrix &A_EH = a_EH->SpMat();
// MixedBilinearForm *a_HE = new MixedBilinearForm(NDfespace, NDfespace);
// a_HE->AddDomainIntegrator(new MixedVectorWeakCurlIntegrator(neg));
// a_HE->AddDomainIntegrator(new MixedVectorCurlIntegrator(neg));
// a_HE->Assemble();
// a_HE->EliminateTestDofs(ess_bdr);
// a_HE->Finalize();
// SparseMatrix &A_HE = a_HE->SpMat();
SparseMatrix &A_HE = *Transpose(A_EH);
BilinearForm *a_HH = new BilinearForm(NDfespace);
a_HH->AddDomainIntegrator(new CurlCurlIntegrator(one)); // one is the coeff
a_HH->AddDomainIntegrator(new VectorFEMassIntegrator(sigma));
a_HH->Assemble();
a_HH->Finalize();
SparseMatrix &A_HH = a_HH->SpMat();
BlockMatrix *LS_Maxwellop = new BlockMatrix(block_offsets);
LS_Maxwellop->SetBlock(0, 0, &A_EE);
LS_Maxwellop->SetBlock(0, 1, &A_HE);
LS_Maxwellop->SetBlock(1, 0, &A_EH);
LS_Maxwellop->SetBlock(1, 1, &A_HH);
SparseMatrix * S = LS_Maxwellop->CreateMonolithic();
UMFPackSolver *invE = new UMFPackSolver;
invE->Control[UMFPACK_ORDERING] = UMFPACK_ORDERING_METIS;
invE->SetOperator(LS_Maxwellop->GetBlock(0,0));
UMFPackSolver *invH = new UMFPackSolver;
invH->Control[UMFPACK_ORDERING] = UMFPACK_ORDERING_METIS;
invH->SetOperator(LS_Maxwellop->GetBlock(1,1));
BlockDiagonalPreconditioner *prec = new BlockDiagonalPreconditioner(block_offsets);
prec->SetDiagonalBlock(0, invE);
prec->SetDiagonalBlock(1, invH);
BlkSchwarzSmoother * M = new BlkSchwarzSmoother(cmesh,ref_levels, NDfespace, S);
M->SetNumSmoothSteps(smth_maxit);
M->SetDumpingParam(theta);
cout << "Size of fine grid system: "
<< 2.0 * A_EE.NumRows() << " x " << 2.0 * A_EE.NumCols() << endl;
int maxit(100);
double rtol(1.e-6);
double atol(0.0);
x = 0.0;
CGSolver pcg;
// GMRESSolver pcg;
pcg.SetAbsTol(atol);
pcg.SetRelTol(rtol);
pcg.SetMaxIter(maxit);
pcg.SetPreconditioner(*M);
pcg.SetOperator(*LS_Maxwellop);
// pcg.SetOperator(*S);
// pcg.SetPreconditioner(*prec);
pcg.SetPrintLevel(1);
pcg.Mult(b, x);
E_gf->MakeRef(NDfespace, x.GetBlock(0), 0);
H_gf->MakeRef(NDfespace, x.GetBlock(1), 0);
int order_quad = max(2, 2 * order + 1);
const IntegrationRule *irs[Geometry::NumGeom];
for (int i = 0; i < Geometry::NumGeom; ++i)
{
irs[i] = &(IntRules.Get(i, order_quad));
}
double Error_E = E_gf->ComputeL2Error(*Eex, irs);
double Error_H;
Error_H = H_gf->ComputeL2Error(*Hex, irs);
cout << "|| E_h - E || = " << Error_E << "\n";
cout << "|| H_h - H || = " << Error_H << "\n";
cout << "Total error = " << sqrt(Error_H*Error_H+Error_E*Error_E) << "\n";
GridFunction *E_exgf = new GridFunction(NDfespace);
E_exgf->ProjectCoefficient(*Eex);
GridFunction *H_exgf = new GridFunction(NDfespace);
if (visualization)
{
char vishost[] = "localhost";
int visport = 19916;
// socketstream cmesh_sock(vishost, visport);
// cmesh_sock.precision(8);
// socketstream mesh_sock(vishost, visport);
// mesh_sock.precision(8);
socketstream sol_sock(vishost, visport);
sol_sock.precision(8);
socketstream ex_sock(vishost, visport);
ex_sock.precision(8);
socketstream sol_sockH(vishost, visport);
sol_sockH.precision(8);
socketstream ex_sockH(vishost, visport);
ex_sockH.precision(8);
if (dim == 2)
{
sol_sock << "solution\n"
<< *mesh << *E_gf << "window_title 'Numerical E'" << "keys rRljc\n"
<< flush;
ex_sock << "solution\n"
<< *mesh << *E_exgf << "window_title 'Exact E'" << "keys rRljc\n"
<< flush;
sol_sockH << "solution\n"
<< *mesh << *H_gf << "window_title 'Numerical H'" << "keys rRljc\n"
<< flush;
ex_sockH << "solution\n"
<< *mesh << *H_exgf << "window_title 'Exact H'" << "keys rRljc\n"
<< flush;
}
else
{
sol_sock << "solution\n"
<< *mesh << *E_gf << "keys lc\n"
<< flush;
ex_sock << "solution\n"
<< *mesh << *E_exgf << "keys lc\n"
<< flush;
}
}
delete a_EE;
delete a_EH;
delete a_HH;
delete b_E;
delete b_H;
delete NDfec;
delete NDfespace;
return 0;
}
//define exact solution
void E_exact(const Vector &x, Vector &E)
{
double curlE[3], curl2E[3];
get_maxwell_solution(x, E, curlE, curl2E);
}
void H_exact(const Vector &x, Vector &H)
{
double E[3], curlE[3], curl2E[3];
get_maxwell_solution(x, E, curlE, curl2E);
for (int i = 0; i < dim; i++) H(i) = curlE[i] / omega;
}
void f_exact_H(const Vector &x, Vector &f)
{
double E[3], curlE[3], curl2E[3];
get_maxwell_solution(x, E, curlE, curl2E);
// curl H - omega E = f
// = curl (curl E / omega) - omega E
f(0) = curl2E[0] / omega - omega * E[0];
f(1) = curl2E[1] / omega - omega * E[1];
f(2) = curl2E[2] / omega - omega * E[2];
}
void scaledf_exact_H(const Vector &x, Vector &f)
{
double E[3], curlE[3], curl2E[3];
get_maxwell_solution(x, E, curlE, curl2E);
// curl H - omega E = f
// = - omega *( curl (curl E / omega) - omega E)
f(0) = -omega * (curl2E[0] / omega - omega * E[0]);
f(1) = -omega * (curl2E[1] / omega - omega * E[1]);
f(2) = -omega * (curl2E[2] / omega - omega * E[2]);
}
void get_maxwell_solution(const Vector &X, double E[], double curlE[], double curl2E[])
{
double x = X[0];
double y = X[1];
double z = X[2];
if (sol == 0) // polynomial
{
// Polynomial vanishing on the boundary
E[0] = y * z * (1.0 - y) * (1.0 - z);
E[1] = (1.0 - x) * x * y * (1.0 - z) * z;
E[2] = (1.0 - x) * x * (1.0 - y) * y;
//
curlE[0] = -(-1.0 + x) * x * (1.0 + y * (-3.0 + 2.0 * z));
curlE[1] = -2.0 * (-1.0 + y) * y * (x - z);
curlE[2] = (1.0 + (-3.0 + 2.0 * x) * y) * (-1.0 + z) * z;
curl2E[0] = -2.0 * (-1.0 + y) * y + (-3.0 + 2.0 * x) * (-1.0 + z) * z;
curl2E[1] = -2.0 * y * (-x + x * x + (-1.0 + z) * z);
curl2E[2] = -2.0 * (-1.0 + y) * y + (-1.0 + x) * x * (-3.0 + 2.0 * z);
}
else if (sol == 1) // sinusoidal
{
E[0] = sin(omega * y);
E[1] = sin(omega * z);
E[2] = sin(omega * x);
curlE[0] = -omega * cos(omega * z);
curlE[1] = -omega * cos(omega * x);
curlE[2] = -omega * cos(omega * y);
curl2E[0] = omega * omega * E[0];
curl2E[1] = omega * omega * E[1];
curl2E[2] = omega * omega * E[2];
}
else if (sol == 2) // point source
{
MFEM_ABORT("Case unfinished");
}
else if (sol == 3) // plane wave
{
double coeff = omega / sqrt(3.0);
E[0] = cos(coeff * (x + y + z));
E[1] = 0.0;
E[2] = 0.0;
curlE[0] = 0.0;
curlE[1] = -coeff * sin(coeff * (x + y + z));
curlE[2] = coeff * sin(coeff * (x + y + z));
curl2E[0] = 2.0 * coeff * coeff * E[0];
curl2E[1] = -coeff * coeff * E[0];
curl2E[2] = -coeff * coeff * E[0];
}
else if (sol == -1)
{
E[0] = cos(omega * y);
E[1] = 0.0;
curlE[0] = 0.0;
curlE[1] = 0.0;
curlE[2] = -omega * sin(omega * y);
curl2E[0] = omega*omega * cos(omega*y);
curl2E[1] = 0.0;
curl2E[2] = 0.0;
}
}