int main( int argc, char** argv )
{
LibMeshInit init (argc, argv);
Mesh mesh(init.comm());
MeshTools::Generation::build_square (mesh,
4, 4,
0.0, 1.0,
0.0, 1.0,
QUAD4);
// XdrIO mesh_io(mesh);
// mesh_io.read("one_tri.xda");
mesh.print_info();
EquationSystems es (mesh);
LinearImplicitSystem& system = es.add_system<LinearImplicitSystem>("lap");
uint u_var = system.add_variable("u", FIRST, LAGRANGE);
Laplacian lap(es);
system.attach_assemble_object(lap);
std::set<boundary_id_type> bd_ids;
bd_ids.insert(1);
bd_ids.insert(3);
std::vector<uint> vars(1,u_var);
ZeroFunction<Real> zero;
DirichletBoundary dirichlet_bc(bd_ids, vars, &zero);
system.get_dof_map().add_dirichlet_boundary(dirichlet_bc);
es.init();
es.print_info();
system.solve();
VTKIO(mesh).write_equation_systems("lap.pvtu",es);
return 0;
}
void setUp()
{
this->build_mesh();
// libMesh *should* renumber now, or a ParallelMesh might not have
// contiguous ids, which is a requirement to write xda files.
_mesh->allow_renumbering(true);
_es = new EquationSystems(*_mesh);
_sys = &_es->add_system<System> ("SimpleSystem");
_sys->add_variable("u", FIRST);
_es->init();
SlitFunc slitfunc;
_sys->project_solution(&slitfunc);
#ifdef LIBMESH_ENABLE_AMR
MeshRefinement(*_mesh).uniformly_refine(1);
_es->reinit();
MeshRefinement(*_mesh).uniformly_refine(1);
_es->reinit();
#endif
}
void setup(EquationSystems& systems, Mesh& mesh, GetPot& args)
{
const unsigned int dim = mesh.mesh_dimension();
// We currently invert tensors with the assumption that they're 3x3
libmesh_assert (dim == 3);
// Generating Mesh
ElemType eltype = Utility::string_to_enum<ElemType>(args("mesh/generation/element_type", "hex8"));
int nx = args("mesh/generation/num_elem", 4, 0);
int ny = args("mesh/generation/num_elem", 4, 1);
int nz = dim > 2 ? args("mesh/generation/num_elem", 4, 2) : 0;
double origx = args("mesh/generation/origin", -1.0, 0);
double origy = args("mesh/generation/origin", -1.0, 1);
double origz = args("mesh/generation/origin", 0.0, 2);
double sizex = args("mesh/generation/size", 2.0, 0);
double sizey = args("mesh/generation/size", 2.0, 1);
double sizez = args("mesh/generation/size", 2.0, 2);
MeshTools::Generation::build_cube(mesh, nx, ny, nz,
origx, origx+sizex, origy, origy+sizey, origz, origz+sizez, eltype);
// Creating Systems
SolidSystem& imms = systems.add_system<SolidSystem> ("solid");
imms.args = args;
// Build up auxiliary system
ExplicitSystem& aux_sys = systems.add_system<TransientExplicitSystem>("auxiliary");
// Initialize the system
systems.parameters.set<unsigned int>("phase") = 0;
systems.init();
imms.save_initial_mesh();
// Fill global solution vector from local ones
aux_sys.reinit();
}
int main (int argc, char** argv)
{
LibMeshInit init(argc, argv);
if (argc < 4)
libMesh::out << "Usage: ./prog -d DIM filename" << std::endl;
// Variables to get us started
const unsigned int dim = atoi(argv[2]);
std::string meshname (argv[3]);
// declare a mesh...
Mesh mesh(init.comm(), dim);
// Read a mesh
mesh.read(meshname);
GMVIO(mesh).write ("out_0.gmv");
mesh.elem(0)->set_refinement_flag (Elem::REFINE);
MeshRefinement mesh_refinement (mesh);
mesh_refinement.refine_and_coarsen_elements ();
mesh_refinement.uniformly_refine (2);
mesh.print_info();
// Set up the equation system(s)
EquationSystems es (mesh);
LinearImplicitSystem& primary =
es.add_system<LinearImplicitSystem>("primary");
primary.add_variable ("U", FIRST);
primary.add_variable ("V", FIRST);
primary.get_dof_map()._dof_coupling->resize(2);
(*primary.get_dof_map()._dof_coupling)(0,0) = 1;
(*primary.get_dof_map()._dof_coupling)(1,1) = 1;
primary.attach_assemble_function(assemble);
es.init ();
es.print_info ();
primary.get_dof_map().print_dof_constraints ();
// call the solver.
primary.solve ();
GMVIO(mesh).write_equation_systems ("out_1.gmv",
es);
// Refine uniformly
mesh_refinement.uniformly_refine (1);
es.reinit ();
// Write out the projected solution
GMVIO(mesh).write_equation_systems ("out_2.gmv",
es);
// Solve again. Output the refined solution
primary.solve ();
GMVIO(mesh).write_equation_systems ("out_3.gmv",
es);
return 0;
}
void assemble_and_solve(MeshBase & mesh,
EquationSystems & equation_systems)
{
mesh.print_info();
LinearImplicitSystem & system =
equation_systems.add_system<LinearImplicitSystem> ("Poisson");
unsigned int u_var = system.add_variable("u", FIRST, LAGRANGE);
system.attach_assemble_function (assemble_poisson);
// the cube has boundaries IDs 0, 1, 2, 3, 4 and 5
std::set<boundary_id_type> boundary_ids;
for (int j = 0; j<6; ++j)
boundary_ids.insert(j);
// Create a vector storing the variable numbers which the BC applies to
std::vector<unsigned int> variables(1);
variables[0] = u_var;
ZeroFunction<> zf;
DirichletBoundary dirichlet_bc(boundary_ids,
variables,
&zf);
system.get_dof_map().add_dirichlet_boundary(dirichlet_bc);
equation_systems.init();
equation_systems.print_info();
#ifdef LIBMESH_ENABLE_AMR
MeshRefinement mesh_refinement(mesh);
mesh_refinement.refine_fraction() = 0.7;
mesh_refinement.coarsen_fraction() = 0.3;
mesh_refinement.max_h_level() = 5;
const unsigned int max_r_steps = 2;
for (unsigned int r_step=0; r_step<=max_r_steps; r_step++)
{
system.solve();
if (r_step != max_r_steps)
{
ErrorVector error;
KellyErrorEstimator error_estimator;
error_estimator.estimate_error(system, error);
libMesh::out << "Error estimate\nl2 norm = "
<< error.l2_norm()
<< "\nmaximum = "
<< error.maximum()
<< std::endl;
mesh_refinement.flag_elements_by_error_fraction (error);
mesh_refinement.refine_and_coarsen_elements();
equation_systems.reinit();
}
}
#else
system.solve();
#endif
}
