Files
mfem/examples/dfem_objective.cpp
T

115 lines
3.0 KiB
C++

#include "dfem.hpp"
int main(int argc, char *argv[])
{
Mpi::Init();
std::cout << std::setprecision(9);
const char *mesh_file = "../data/star.mesh";
int polynomial_order = 1;
int refinements = 0;
OptionsParser args(argc, argv);
args.AddOption(&mesh_file, "-m", "--mesh", "Mesh file to use.");
args.AddOption(&polynomial_order, "-o", "--order", "");
args.AddOption(&refinements, "-r", "--r", "");
args.ParseCheck();
Mesh mesh_serial(mesh_file, 1, 1);
mesh_serial.SetCurvature(1);
for (int i = 0; i < refinements; i++)
{
mesh_serial.UniformRefinement();
}
const int dim = mesh_serial.Dimension();
ParMesh mesh(MPI_COMM_WORLD, mesh_serial);
mesh_serial.Clear();
constexpr int vdim = 2;
// test_partial_assembly_setup_qf(mesh, 1, polynomial_order);
// exit(0);
H1_FECollection h1fec(polynomial_order, dim);
ParFiniteElementSpace h1fes(&mesh, &h1fec, vdim);
Array<int> ess_tdof_list;
Array<int> ess_bdr(mesh.bdr_attributes.Max());
ess_bdr = 1;
h1fes.GetEssentialTrueDofs(ess_bdr, ess_tdof_list);
const IntegrationRule &ir =
IntRules.Get(h1fes.GetFE(0)->GetGeomType(), 2 * h1fec.GetOrder() + 1);
std::cout << "nqpts = " << ir.GetNPoints() << std::endl;
std::cout << "ndofs = " << h1fes.GlobalTrueVSize() << std::endl;
ParGridFunction u(&h1fes);
ParGridFunction g(&h1fes);
ParGridFunction rho(&h1fes);
auto exact_solution = [](const Vector &coords, Vector &u)
{
const double x = coords(0);
const double y = coords(1);
u(0) = x*x + y;
u(1) = x + 0.5*y*y;
};
VectorFunctionCoefficient exact_solution_coeff(dim, exact_solution);
auto objective = [](tensor<double, 2> u, double rho,
tensor<double, 2, 2> J,
double w)
{
return sqnorm(u) * det(J) * w;
};
std::tuple inputs{Value{"displacement"}, Value{"density"}, Gradient{"coordinates"}, Weight{"integration_weight"}};
std::tuple outputs{ One{"integral"} };
ElementOperator objective_eop { objective, inputs, outputs };
std::vector<Field> solution_fields{{&u, "displacement"}};
std::vector<Field> parameter_fields{{mesh.GetNodes(), "coordinates"}, {&rho, "density"}};
std::vector<Field> dependent_variables{{&u, "displacement"}};
DifferentiableForm dop(solution_fields, parameter_fields, dependent_variables,
mesh);
dop.AddElementOperator(objective_eop, ir);
u.ProjectCoefficient(exact_solution_coeff);
Vector zero;
Vector y(1);
Vector utdof;
u.GetTrueDofs(utdof);
dop.Mult(utdof, y);
// finite difference test
Vector dgdu(u.Size());
Vector fx(y);
out << "g: ";
print_vector(fx);
out << "\n";
for (int i = 0; i < u.Size(); i++)
{
double h = 1e-6;
u(i) += h;
dop.Mult(u, y);
u(i) -= h;
y -= fx;
y /= h;
dgdu(i) = y(0);
}
out << "dgdu: ";
print_vector(dgdu);
// Vector dgdu = dop.GetGradientWrt({&u, "displacement"});
return 0;
}