//! Compute the number of dof of given FEM
void set (
const getfem::mesh_fem & mf_Ut, const getfem::mesh_fem & mf_Pt,
const std::vector<getfem::mesh_fem> & mf_Uv, const getfem::mesh_fem & mf_Pv,
const getfem::mesh_fem & mf_coeft, const getfem::mesh_fem & mf_coefv
)
{
Ut_ = mf_Ut.nb_dof();
Pt_ = mf_Pt.nb_dof();
ct_ = mf_coeft.nb_dof();
Uv_ = 0;
for (size_type i = 0; i<mf_Uv.size(); ++i) Uv_ += mf_Uv[i].nb_dof();
Pv_ = mf_Pv.nb_dof();
cv_ = mf_coefv.nb_dof();
tissue_ = Pt_ + Ut_;
vessel_ = Pv_ + Uv_;
tot_ = tissue_ + vessel_;
}
void acoustics_problem::init(void) {
cout << "Initializing problem..." << endl;
// define the parameters
residual = 1E-9;
std::string MESH_TYPE = PARAM.string_value("MESH_TYPE");
std::string FEM_TYPE = PARAM.string_value("FEM_TYPE");
std::string INTEGRATION = PARAM.string_value("INTEGRATION");
datafilename = "acoustics";
k2 = PARAM.real_value("k2");
c2 = PARAM.real_value("c2");
a4 = PARAM.int_value("A4");
omega = PARAM.int_value("omega");
gama = PARAM.int_value("gama");
cout << "MESH_TYPE=" << MESH_TYPE << "\n";
cout << "FEM_TYPE=" << FEM_TYPE << "\n";
cout << "INTEGRATION=" << INTEGRATION << "\n";
// mesh
std::string meshname("gmsh:../mesh/" + datafilename + ".msh");
getfem::import_mesh(meshname, mesh);
N = mesh.dim();
mesh.optimize_structure();
// set the finite element on the mf_u
getfem::pfem pf_u = getfem::fem_descriptor(FEM_TYPE);
getfem::pintegration_method ppi = getfem::int_method_descriptor(INTEGRATION);
mim.set_integration_method(mesh.convex_index(), ppi);
mf_u.set_finite_element(mesh.convex_index(), pf_u);
mf_rhs.set_finite_element(mesh.convex_index(), pf_u);
mf_rhs.set_qdim(N);
}
bool acoustics_problem::solve(void) {
cout << "Solving Problem..." << endl;
// define the model to solve
getfem::model model;
// Main unknown of the problem
model.add_fem_variable("u", mf_u, 2);
plain_vector K(1);
K[0] = k2;
model.add_initialized_fixed_size_data("k2", K);
getfem::add_Helmholtz_brick(model, mim, "u", "k2", omega);
// TODO: model and boundary conditions definition
/*// Laplacian with constant
model.add_initialized_scalar_data("c2", c2);
getfem::add_generic_elliptic_brick(model, mim, "u", "c2", omega);
// other term in the Helmholtz equation
model.add_initialized_scalar_data("k2", k2);
getfem::add_mass_brick(model, mim, "u", "k2");
*/
plain_vector G;
gmm::resize(G, mf_rhs.nb_dof());
// Neumann Boundary condition
getfem::interpolation_function(mf_u, G, sol_g, a4);
model.add_initialized_fem_data("g", mf_u, G);
getfem::add_normal_source_term_brick(model, mim, "u", "g", a4);
getfem::add_normal_source_term_brick(model, mim, "u", "g", gama);
gmm::iteration iter(residual, 0, 40000);
model.first_iter();
// Null initial value
gmm::resize(U, mf_u.nb_dof());
gmm::clear(U);
gmm::copy(U, model.set_real_variable("u", 1));
// exporting to vtk format
getfem::stored_mesh_slice sl;
sl.build(mesh, getfem::slicer_none(), 4);
getfem::vtk_export exp(datafilename + ".vtk");
exp.exporting(mf_u);
exp.write_point_data(mf_u, U, "sound");
plain_vector F;
gmm::resize(F, mf_rhs.nb_dof());
getfem::interpolation_function(mf_rhs, F, sol_g);
gmm::copy(F, model.set_real_variable("g"));
iter.init();
getfem::standard_solve(model, iter);
gmm::copy(model.real_variable("u"), U);
exp.write_point_data(mf_u, U, "sound");
return (iter.converged());
}