Esempio n. 1
0
int main(int argc, char **args) 
{
  // Time measurement.
  TimePeriod cpu_time;
  cpu_time.tick();

  // Load the mesh. 
  Mesh mesh;

  //CTUReader mloader;
  H3DReader mloader;

  info("Loading mesh...");
  mloader.load("bridge.mesh3d", &mesh);

  // Create H1 space with default shapeset.
  H1Space space(&mesh, bc_types, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));

  // Initialize weak formulation. 
  WeakForm wf;
  wf.add_matrix_form(bilinear_form<double, scalar>, bilinear_form<Ord, Ord>, HERMES_SYM);
  wf.add_vector_form(linear_form<double, scalar>, linear_form<Ord, Ord>, HERMES_ANY_INT);

  // Initialize discrete problem.
  bool is_linear = true;
  DiscreteProblem dp(&wf, &space, is_linear);

  // Set up the solver, matrix, and rhs according to the solver selection.
  SparseMatrix* matrix = create_matrix(matrix_solver);
  Vector* rhs = create_vector(matrix_solver);
  Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);

  // Assemble stiffness matrix and load vector.
  info("Assembling the linear problem (ndof: %d).", Space::get_num_dofs(&space));
  dp.assemble(matrix, rhs);

  // Solve the linear system. If successful, obtain the solution.
  info("Solving the linear problem.");
  Solution sln(&mesh);
  if(solver->solve()) Solution::vector_to_solution(solver->get_solution(), &space, &sln);
  else error ("Matrix solver failed.\n");

  // Output the solution for Paraview.
  if (solution_output) out_fn_vtk(&sln, "sln");

  // Time measurement.
  cpu_time.tick();

  // Print timing information.
  info("Solutions and mesh with polynomial orders saved. Total running time: %g s", 
       cpu_time.accumulated());

  // Clean up.
  delete matrix;
  delete rhs;
  delete solver;

  return 0;
}
Esempio n. 2
0
int main(int argc, char **args) 
{
  // Time measurement.
  TimePeriod cpu_time;
  cpu_time.tick();

  // Load the mesh. 
  Mesh mesh;
  ExodusIIReader mloader;
  mloader.load("brick_with_hole_hex.e", &mesh);

  // Perform initial mesh refinement. 
  for (int i=0; i < INIT_REF_NUM; i++) mesh.refine_all_elements(H3D_H3D_H3D_REFT_HEX_XYZ);

  // Create H1 space with default shapeset for x-displacement component. 
  H1Space xdisp(&mesh, bc_types_x, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));
  
  // Create H1 space with default shapeset for y-displacement component. 
  H1Space ydisp(&mesh, bc_types_y, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));
  
  // Create H1 space with default shapeset for z-displacement component. 
  H1Space zdisp(&mesh, bc_types_z, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));
  
  // Initialize weak formulation.
  WeakForm wf(3);
  wf.add_matrix_form(0, 0, callback(bilinear_form_0_0), HERMES_SYM);
  wf.add_matrix_form(0, 1, callback(bilinear_form_0_1), HERMES_SYM);
  wf.add_matrix_form(0, 2, callback(bilinear_form_0_2), HERMES_SYM);
  wf.add_vector_form_surf(0, callback(surf_linear_form_x), bdy_force);

  wf.add_matrix_form(1, 1, callback(bilinear_form_1_1), HERMES_SYM);
  wf.add_matrix_form(1, 2, callback(bilinear_form_1_2), HERMES_SYM);
  wf.add_vector_form_surf(1, callback(surf_linear_form_y), bdy_force);

  wf.add_matrix_form(2, 2, callback(bilinear_form_2_2), HERMES_SYM);
  wf.add_vector_form_surf(2, callback(surf_linear_form_z), bdy_force);

  // Initialize discrete problem.
  bool is_linear = true;
  DiscreteProblem dp(&wf, Hermes::Tuple<Space *>(&xdisp, &ydisp, &zdisp), is_linear);

  // Set up the solver, matrix, and rhs according to the solver selection.
  SparseMatrix* matrix = create_matrix(matrix_solver);
  Vector* rhs = create_vector(matrix_solver);
  Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);

  // Initialize the preconditioner in the case of SOLVER_AZTECOO.
  if (matrix_solver == SOLVER_AZTECOO) 
  {
    ((AztecOOSolver*) solver)->set_solver(iterative_method);
    ((AztecOOSolver*) solver)->set_precond(preconditioner);
    // Using default iteration parameters (see solver/aztecoo.h).
  }

  // Assemble stiffness matrix and load vector.
  info("Assembling the linear problem (ndof: %d).", Space::get_num_dofs(Hermes::Tuple<Space *>(&xdisp, &ydisp, &zdisp)));
  dp.assemble(matrix, rhs);

  // Solve the linear system. If successful, obtain the solution.
  info("Solving the linear problem.");
  Solution xsln(xdisp.get_mesh());
  Solution ysln(ydisp.get_mesh());
  Solution zsln(zdisp.get_mesh());
  if(solver->solve()) Solution::vector_to_solutions(solver->get_solution(), 
                      Hermes::Tuple<Space *>(&xdisp, &ydisp, &zdisp), Hermes::Tuple<Solution *>(&xsln, &ysln, &zsln));
  else error ("Matrix solver failed.\n");

  // Output all components of the solution.
  if (solution_output) out_fn_vtk(&xsln, &ysln, &zsln, "sln");
  
  // Time measurement.
  cpu_time.tick();

  // Print timing information.
  info("Solutions saved. Total running time: %g s.", cpu_time.accumulated());

  // Clean up.
  delete matrix;
  delete rhs;
  delete solver;
  
  return 0;
}
Esempio n. 3
0
int main(int argc, char **args) 
{
  // Load the mesh.
  Mesh mesh;
  H3DReader mesh_loader;
  mesh_loader.load("fichera-corner.mesh3d", &mesh);

  // Perform initial mesh refinement.
  for (int i=0; i < INIT_REF_NUM; i++) mesh.refine_all_elements(H3D_H3D_H3D_REFT_HEX_XYZ);

  // Create an H1 space with default shapeset.
  H1Space space(&mesh, bc_types, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));

  // Initialize weak formulation.
  WeakForm wf;
  wf.add_matrix_form(bilinear_form<double, double>, bilinear_form<Ord, Ord>, HERMES_SYM, HERMES_ANY);
  wf.add_vector_form(linear_form<double, double>, linear_form<Ord, Ord>, HERMES_ANY);

  // Set exact solution.
  ExactSolution exact(&mesh, fndd);

  // DOF and CPU convergence graphs.
  SimpleGraph graph_dof_est, graph_cpu_est, graph_dof_exact, graph_cpu_exact;

  // Time measurement.
  TimePeriod cpu_time;
  cpu_time.tick();

  // Initialize the solver in the case of SOLVER_PETSC or SOLVER_MUMPS.
  initialize_solution_environment(matrix_solver, argc, args);

  // Adaptivity loop. 
  int as = 1; 
  bool done = false;
  do 
  {
    info("---- Adaptivity step %d:", as);

    // Construct globally refined reference mesh and setup reference space.
    Space* ref_space = construct_refined_space(&space,1 , H3D_H3D_H3D_REFT_HEX_XYZ);

    // Initialize discrete problem.
    bool is_linear = true;
    DiscreteProblem dp(&wf, ref_space, is_linear);

    // Set up the solver, matrix, and rhs according to the solver selection.
    SparseMatrix* matrix = create_matrix(matrix_solver);
    Vector* rhs = create_vector(matrix_solver);
    Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);
    
    // Initialize the preconditioner in the case of SOLVER_AZTECOO.
    if (matrix_solver == SOLVER_AZTECOO) 
    {
      ((AztecOOSolver*) solver)->set_solver(iterative_method);
      ((AztecOOSolver*) solver)->set_precond(preconditioner);
      // Using default iteration parameters (see solver/aztecoo.h).
    }
  
    // Assemble the reference problem.
    info("Assembling on reference mesh (ndof: %d).", Space::get_num_dofs(ref_space));
    dp.assemble(matrix, rhs);

    // Time measurement.
    cpu_time.tick();

    // Solve the linear system on reference mesh. If successful, obtain the solution.
    info("Solving on reference mesh.");
    Solution ref_sln(ref_space->get_mesh());
    if(solver->solve()) Solution::vector_to_solution(solver->get_solution(), ref_space, &ref_sln);
    else error ("Matrix solver failed.\n");

    // Time measurement.
    cpu_time.tick();

    // Project the reference solution on the coarse mesh.
    Solution sln(space.get_mesh());
    info("Projecting reference solution on coarse mesh.");
    OGProjection::project_global(&space, &ref_sln, &sln, matrix_solver);

    // Time measurement.
    cpu_time.tick();

    // Output solution and mesh with polynomial orders.
    if (solution_output) 
    {
      out_fn_vtk(&sln, "sln", as);
      out_orders_vtk(&space, "order", as);
    }

    // Skip the visualization time.
    cpu_time.tick(HERMES_SKIP);

    // Calculate element errors and total error estimate.
    info("Calculating error estimate and exact error.");
    Adapt *adaptivity = new Adapt(&space, HERMES_H1_NORM);
    bool solutions_for_adapt = true;
    double err_est_rel = adaptivity->calc_err_est(&sln, &ref_sln, solutions_for_adapt) * 100;

    // Calculate exact error.
    solutions_for_adapt = false;
    double err_exact_rel = adaptivity->calc_err_exact(&sln, &exact, solutions_for_adapt) * 100;

    // Report results.
    info("ndof_coarse: %d, ndof_fine: %d.", Space::get_num_dofs(&space), Space::get_num_dofs(ref_space));
    info("err_est_rel: %g%%, err_exact_rel: %g%%.", err_est_rel, err_exact_rel);

    // Add entry to DOF and CPU convergence graphs.
    graph_dof_est.add_values(Space::get_num_dofs(&space), err_est_rel);
    graph_dof_est.save("conv_dof_est.dat");
    graph_cpu_est.add_values(cpu_time.accumulated(), err_est_rel);
    graph_cpu_est.save("conv_cpu_est.dat");
    graph_dof_exact.add_values(Space::get_num_dofs(&space), err_exact_rel);
    graph_dof_exact.save("conv_dof_exact.dat");
    graph_cpu_exact.add_values(cpu_time.accumulated(), err_exact_rel);
    graph_cpu_exact.save("conv_cpu_exact.dat");

    // If err_est_rel is too large, adapt the mesh. 
    if (err_est_rel < ERR_STOP) done = true;
    else 
    {
      info("Adapting coarse mesh.");
      adaptivity->adapt(THRESHOLD);
    }
    if (Space::get_num_dofs(&space) >= NDOF_STOP) done = true;

    // Clean up.
    delete ref_space->get_mesh();
    delete ref_space;
    delete matrix;
    delete rhs;
    delete solver;
    delete adaptivity;

    // Increase the counter of performed adaptivity steps.
    as++;
  } while (!done);

  // Properly terminate the solver in the case of SOLVER_PETSC or SOLVER_MUMPS.
  finalize_solution_environment(matrix_solver);

  return 1;
}
Esempio n. 4
0
int main (int argc, char* argv[]) {
  
  // Load the mesh. 
  Mesh basemesh;
  ExodusIIReader mesh_loader;
  if (!mesh_loader.load("coarse_mesh_full.e", &basemesh))
    error("Loading mesh file '%s' failed.\n", "coarse_mesh_full.e");

  Mesh C_mesh, phi_mesh;
  C_mesh.copy(basemesh);

  phi_mesh.copy(basemesh);

  H1Space C_space(&C_mesh, bc_types_C, essential_bc_values_C, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));
  H1Space phi_space(MULTIMESH ? &phi_mesh : &C_mesh, bc_types_phi, essential_bc_values_phi, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));

  Solution C_prev_time(&C_mesh);
  C_prev_time.set_const(C0);
  Solution phi_prev_time(MULTIMESH ? &phi_mesh : &C_mesh);
  phi_prev_time.set_const(0.0);


  WeakForm wf(2);
  // Add the bilinear and linear forms.
  if (TIME_DISCR == 1) {  // Implicit Euler.
  wf.add_matrix_form(0, 0, callback(J_euler_DFcDYc), HERMES_NONSYM);
  wf.add_matrix_form(0, 1, callback(J_euler_DFcDYphi), HERMES_NONSYM);
  wf.add_matrix_form(1, 0, callback(J_euler_DFphiDYc), HERMES_NONSYM);
  wf.add_matrix_form(1, 1, callback(J_euler_DFphiDYphi), HERMES_NONSYM);
  wf.add_vector_form(0, callback(Fc_euler), HERMES_ANY_INT,
                     Hermes::vector<MeshFunction*>(&C_prev_time, &phi_prev_time));
  wf.add_vector_form(1, callback(Fphi_euler), HERMES_ANY,
                     Hermes::vector<MeshFunction*>(&C_prev_time, &phi_prev_time));
  } else {
    wf.add_matrix_form(0, 0, callback(J_cranic_DFcDYc), HERMES_NONSYM);
    wf.add_matrix_form(0, 1, callback(J_cranic_DFcDYphi), HERMES_NONSYM);
    wf.add_matrix_form(1, 0, callback(J_cranic_DFphiDYc), HERMES_NONSYM);
    wf.add_matrix_form(1, 1, callback(J_cranic_DFphiDYphi), HERMES_NONSYM);
    wf.add_vector_form(0, callback(Fc_cranic), HERMES_ANY,
                       Hermes::vector<MeshFunction*>(&C_prev_time, &phi_prev_time));
    wf.add_vector_form(1, callback(Fphi_cranic), HERMES_ANY);
  }

  int ndof = Space::get_num_dofs(Hermes::vector<Space*>(&C_space, &phi_space));

  Solution C_sln(C_space.get_mesh());
  Solution phi_sln(phi_space.get_mesh());

  info("Projecting initial condition to obtain initial vector for the Newton's method.");
  scalar* coeff_vec_coarse = new scalar[ndof];
  OGProjection::project_global(Hermes::vector<Space *>(&C_space, &phi_space),
                               Hermes::vector<MeshFunction *>(&C_prev_time, &phi_prev_time),
                               coeff_vec_coarse, matrix_solver);



  bool is_linear = false;
  DiscreteProblem dp_coarse(&wf, Hermes::vector<Space *>(&C_space, &phi_space), is_linear);

  //Solution::vector_to_solutions(coeff_vec_coarse, dp_coarse.get_spaces(), Hermes::vector<Solution *>(&C_sln, &phi_sln), NULL);


  // Set up the solver, matrix, and rhs for the coarse mesh according to the solver selection.
  SparseMatrix* matrix_coarse = create_matrix(matrix_solver);
  Vector* rhs_coarse = create_vector(matrix_solver);
  Solver* solver_coarse = create_linear_solver(matrix_solver, matrix_coarse, rhs_coarse);

  info("Solving on coarse mesh:");
  bool verbose = true;
  if (!solve_newton(coeff_vec_coarse, &dp_coarse, solver_coarse, matrix_coarse, rhs_coarse,
      NEWTON_TOL_COARSE, NEWTON_MAX_ITER, verbose)) error("Newton's iteration failed.");

  info("Solved!");
  // Translate the resulting coefficient vector into the Solution sln.
  Solution::vector_to_solutions(coeff_vec_coarse, Hermes::vector<Space *>(&C_space, &phi_space),
                                Hermes::vector<Solution *>(&C_sln, &phi_sln));

  out_fn_vtk(&C_sln,"C_init_sln");
  out_fn_vtk(&phi_sln,"phi_init_sln");
  //out_fn_vtk(&sln, "sln", ts);

  Solution *C_ref_sln, *phi_ref_sln;

  PidTimestepController pid(T_FINAL, false, INIT_TAU);
  TAU = pid.timestep;
  info("Starting time iteration with the step %g", *TAU);
  do {
    pid.begin_step();

    if (pid.get_timestep_number() > 1 && pid.get_timestep_number() % UNREF_FREQ == 0)
    {
      info("Global mesh derefinement.");
      C_mesh.copy(basemesh);
      if (MULTIMESH)
      {
        phi_mesh.copy(basemesh);
      }
      C_space.set_uniform_order(Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));
      phi_space.set_uniform_order(Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));


      }
      bool done = false; int as = 1;
      double err_est;
      do {
        info("Time step %d, adaptivity step %d:", pid.get_timestep_number(), as);

        // Construct globally refined reference mesh
        // and setup reference space.
        int order_increase = 1;
        Hermes::vector<Space *>* ref_spaces = construct_refined_spaces(Hermes::vector<Space *>(&C_space, &phi_space), 
                                                                       order_increase);
        scalar* coeff_vec = new scalar[Space::get_num_dofs(*ref_spaces)];
        DiscreteProblem* dp = new DiscreteProblem(&wf, *ref_spaces, is_linear);
        SparseMatrix* matrix = create_matrix(matrix_solver);
        Vector* rhs = create_vector(matrix_solver);
        Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);


        if (as == 1 && pid.get_timestep_number() == 1) {
          info("Projecting coarse mesh solution to obtain coefficient vector on new fine mesh.");
          OGProjection::project_global(*ref_spaces, Hermes::vector<MeshFunction *>(&C_sln, &phi_sln),
                                       coeff_vec, matrix_solver);
        }
        else {
          info("Projecting previous fine mesh solution to obtain coefficient vector on new fine mesh.");
          OGProjection::project_global(*ref_spaces, Hermes::vector<MeshFunction *>(C_ref_sln, phi_ref_sln),
                                       coeff_vec, matrix_solver);
        }
        if (as > 1) {
          // Now deallocate the previous mesh
          info("Deallocating the previous mesh");
          //delete C_ref_sln->get_mesh();
          //delete phi_ref_sln->get_mesh();
          //delete C_ref_sln;
          //delete phi_ref_sln;
        }
        /*TODO TEMP */
        if (pid.get_timestep_number() > 1) {

        delete C_ref_sln;
        delete phi_ref_sln;
        }

        info("Solving on fine mesh:");
        if (!solve_newton(coeff_vec, dp, solver, matrix, rhs,
              NEWTON_TOL_FINE, NEWTON_MAX_ITER, verbose)) error("Newton's iteration failed.");


        // Store the result in ref_sln.
        C_ref_sln = new Solution(ref_spaces->at(0)->get_mesh());
        phi_ref_sln = new Solution(ref_spaces->at(1)->get_mesh());

        Solution::vector_to_solutions(coeff_vec, *ref_spaces,
                                      Hermes::vector<Solution *>(C_ref_sln, phi_ref_sln));
        // Projecting reference solution onto the coarse mesh
        info("Projecting fine mesh solution on coarse mesh.");
        OGProjection::project_global(Hermes::vector<Space *>(&C_space, &phi_space),
                                     Hermes::vector<Solution *>(C_ref_sln, phi_ref_sln),
                                     Hermes::vector<Solution *>(&C_sln, &phi_sln),
                                     matrix_solver);


        info("Calculating error estimate.");
        Adapt* adaptivity = new Adapt(Hermes::vector<Space *>(&C_space, &phi_space),
            Hermes::vector<ProjNormType> (HERMES_H1_NORM, HERMES_H1_NORM));
        Hermes::vector<double> err_est_rel;
        bool solutions_for_adapt = true;

        double err_est_rel_total = adaptivity->calc_err_est(Hermes::vector<Solution *>(&C_sln, &phi_sln),
            Hermes::vector<Solution *>(C_ref_sln, phi_ref_sln), solutions_for_adapt,
            HERMES_TOTAL_ERROR_REL | HERMES_ELEMENT_ERROR_ABS, &err_est_rel) * 100;

        // Report results.
        info("ndof_coarse[0]: %d, ndof_fine[0]: %d",
             C_space.get_num_dofs(), (*ref_spaces)[0]->get_num_dofs());
        info("err_est_rel[0]: %g%%", err_est_rel[0]*100);
        info("ndof_coarse[1]: %d, ndof_fine[1]: %d",
             phi_space.get_num_dofs(), (*ref_spaces)[1]->get_num_dofs());
        info("err_est_rel[1]: %g%%", err_est_rel[1]*100);
        // Report results.
        info("ndof_coarse_total: %d, ndof_fine_total: %d, err_est_rel: %g%%",
             Space::get_num_dofs(Hermes::vector<Space *>(&C_space, &phi_space)),
                                 Space::get_num_dofs(*ref_spaces), err_est_rel_total);

        // If err_est too large, adapt the mesh.
        if (err_est_rel_total < ERR_STOP) done = true;
        else
        {
          info("Adapting the coarse mesh.");
          adaptivity->adapt(THRESHOLD);

          info("Adapted...");

          if (Space::get_num_dofs(Hermes::vector<Space *>(&C_space, &phi_space)) >= NDOF_STOP)
            done = true;
          else
            // Increase the counter of performed adaptivity steps.
            as++;
        }



        //as++;
        delete solver;
        delete matrix;
        delete rhs;
        delete ref_spaces;
        delete dp;
        delete[] coeff_vec;
        done = true;
      } while (!done);
      out_fn_vtk(C_ref_sln,"C_sln", pid.get_timestep_number());
      out_fn_vtk(phi_ref_sln,"phi_sln", pid.get_timestep_number());

      pid.end_step(Hermes::vector<Solution*> (C_ref_sln, phi_ref_sln), Hermes::vector<Solution*> (&C_prev_time, &phi_prev_time));

      // Copy last reference solution into sln_prev_time.
      C_prev_time.copy(C_ref_sln);
      phi_prev_time.copy(phi_ref_sln);
  } while (pid.has_next());


  //View::wait();
  return 0;
}
Esempio n. 5
0
int main(int argc, char **args)
{
  // Test variable.
  int success_test = 1;

  // Check the number of command-line parameters.
  if (argc < 2) {
    info("Use x, y, z, xy, xz, yz, or xyz as a command-line parameter.");
    error("Not enough command-line parameters.");
  }

  // Determine anisotropy type from the command-line parameter.
  ANISO_TYPE = parse_aniso_type(args[1]);

  // Load the mesh.
  Mesh mesh;
  H3DReader mesh_loader;
  mesh_loader.load("hex-0-1.mesh3d", &mesh);

  // Assign the lowest possible directional polynomial degrees so that the problem's NDOF >= 1.
  assign_poly_degrees();

  // Create an H1 space with default shapeset.
  info("Setting directional polynomial degrees %d, %d, %d.", P_INIT_X, P_INIT_Y, P_INIT_Z);
  H1Space space(&mesh, bc_types, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));

  // Initialize weak formulation.
  WeakForm wf;
  wf.add_matrix_form(bilinear_form<double, scalar>, bilinear_form<Ord, Ord>, HERMES_SYM, HERMES_ANY);
  wf.add_vector_form(linear_form<double, scalar>, linear_form<Ord, Ord>, HERMES_ANY);

  // Set exact solution.
  ExactSolution exact(&mesh, fndd);

  // Time measurement.
  TimePeriod cpu_time;
  cpu_time.tick();

  // Adaptivity loop. 
  int as = 1; 
  bool done = false;
  do 
  {
    info("---- Adaptivity step %d:", as);

    // Construct globally refined reference mesh and setup reference space.
    Space* ref_space = construct_refined_space(&space, 1);

    // Initialize discrete problem.
    bool is_linear = true;
    DiscreteProblem dp(&wf, ref_space, is_linear);

    // Set up the solver, matrix, and rhs according to the solver selection.
    SparseMatrix* matrix = create_matrix(matrix_solver);
    Vector* rhs = create_vector(matrix_solver);
    Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);
    
    // Initialize the preconditioner in the case of SOLVER_AZTECOO.
    if (matrix_solver == SOLVER_AZTECOO) 
    {
      ((AztecOOSolver*) solver)->set_solver(iterative_method);
      ((AztecOOSolver*) solver)->set_precond(preconditioner);
      // Using default iteration parameters (see solver/aztecoo.h).
    }
  
    // Assemble the reference problem.
    info("Assembling on reference mesh (ndof: %d).", Space::get_num_dofs(ref_space));
    dp.assemble(matrix, rhs);

    // Time measurement.
    cpu_time.tick();

    // Solve the linear system on reference mesh. If successful, obtain the solution.
    info("Solving on reference mesh.");
    Solution ref_sln(ref_space->get_mesh());
    if(solver->solve()) Solution::vector_to_solution(solver->get_solution(), ref_space, &ref_sln);
    else {
		  error ("Matrix solver failed.\n");
		  success_test = 0;
	  }

    // Time measurement.
    cpu_time.tick();

    // Project the reference solution on the coarse mesh.
    Solution sln(space.get_mesh());
    info("Projecting reference solution on coarse mesh.");
    OGProjection::project_global(&space, &ref_sln, &sln, matrix_solver);

    // Time measurement.
    cpu_time.tick();

    // Output solution and mesh with polynomial orders.
    if (solution_output) 
    {
      out_fn_vtk(&sln, "sln", as);
      out_orders_vtk(&space, "order", as);
    }

    // Skip the visualization time.
    cpu_time.tick(HERMES_SKIP);

    // Calculate element errors and total error estimate.
    info("Calculating error estimate and exact error.");
    Adapt *adaptivity = new Adapt(&space, HERMES_H1_NORM);
    bool solutions_for_adapt = true;
    double err_est_rel = adaptivity->calc_err_est(&sln, &ref_sln, solutions_for_adapt) * 100;

    // Calculate exact error.
    solutions_for_adapt = false;
    double err_exact_rel = adaptivity->calc_err_exact(&sln, &exact, solutions_for_adapt) * 100;

    // Report results.
    info("ndof_coarse: %d, ndof_fine: %d.", Space::get_num_dofs(&space), Space::get_num_dofs(ref_space));
    info("err_est_rel: %g%%, err_exact_rel: %g%%.", err_est_rel, err_exact_rel);

    // If err_est_rel is too large, adapt the mesh. 
    if (err_est_rel < ERR_STOP) done = true;
    else 
    {
      info("Adapting coarse mesh.");
      adaptivity->adapt(THRESHOLD);
    }
    if (Space::get_num_dofs(&space) >= NDOF_STOP) done = true;

    // Clean up.
    delete ref_space->get_mesh();
    delete ref_space;
    delete matrix;
    delete rhs;
    delete solver;
    delete adaptivity;

    // Increase the counter of performed adaptivity steps.
    as++;
  } while (!done);

  // This is the actual test.
#define ERROR_SUCCESS                               0
#define ERROR_FAILURE                               -1
  int ndof_allowed;
  switch (ANISO_TYPE) {
  case ANISO_X: ndof_allowed = 28; break;
    case ANISO_Y: ndof_allowed = 28; break;
    case ANISO_Z: ndof_allowed = 28; break;
    case ANISO_X | ANISO_Y: ndof_allowed = 98; break;
    case ANISO_X | ANISO_Z: ndof_allowed = 98; break;
    case ANISO_Y | ANISO_Z: ndof_allowed = 98; break;
  case ANISO_X | ANISO_Y | ANISO_Z: ndof_allowed = 343; break; 
    default: error("Admissible command-line options are x, y, x, xy, xz, yz, xyz.");
  }

  int ndof = Space::get_num_dofs(&space);

  info("ndof_actual = %d", ndof);
  info("ndof_allowed = %d", ndof_allowed); 
  if (ndof > ndof_allowed)
    success_test = 0;
  
  if (success_test) {
    info("Success!");
    return ERR_SUCCESS;
  }
  else {
    info("Failure!");
    return ERR_FAILURE;
  }
}
Esempio n. 6
0
int main(int argc, char **args)
{
  // Time measurement.
  TimePeriod cpu_time;
  cpu_time.tick();

  // Load the mesh. 
  Mesh mesh;
  ExodusIIReader mesh_loader;
  if (!mesh_loader.load("cylinder2.e", &mesh))
    error("Loading mesh file '%s' failed.\n", "cylinder2.e");

  // Perform initial mesh refinement.
  for (int i=0; i < INIT_REF_NUM; i++) mesh.refine_all_elements(H3D_H3D_H3D_REFT_HEX_XYZ);
  
  // Create H1 space with default shapeset.
  H1Space space(&mesh, bc_types, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));
  info("Number of DOF: %d.", Space::get_num_dofs(&space));

  // Initialize weak formulation.
  WeakForm wf;
  wf.add_matrix_form(callback(bilinear_form1), HERMES_SYM, 1);
  wf.add_matrix_form(callback(bilinear_form2), HERMES_SYM, 2);
  wf.add_vector_form(callback(linear_form), HERMES_ANY);

  // Initialize discrete problem.
  bool is_linear = true;
  DiscreteProblem dp(&wf, &space, is_linear);

  // Initialize the solver in the case of SOLVER_PETSC or SOLVER_MUMPS.
  initialize_solution_environment(matrix_solver, argc, args);

  // Set up the solver, matrix, and rhs according to the solver selection.  
  SparseMatrix* matrix = create_matrix(matrix_solver);
  Vector* rhs = create_vector(matrix_solver);
  Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);

  // Initialize the preconditioner in the case of SOLVER_AZTECOO.
  if (matrix_solver == SOLVER_AZTECOO) 
  {
    ((AztecOOSolver*) solver)->set_solver(iterative_method);
    ((AztecOOSolver*) solver)->set_precond(preconditioner);
    // Using default iteration parameters (see solver/aztecoo.h).
  }

  // Assemble stiffness amtrix and load vector.
  info("Assembling the linear problem (ndof: %d).", Space::get_num_dofs(&space));
  dp.assemble(matrix, rhs);
	
  // Solve the linear system. If successful, obtain the solution.
  info("Solving the linear problem.");
  Solution sln(space.get_mesh());
  if(solver->solve()) Solution::vector_to_solution(solver->get_solution(), &space, &sln);
  else error ("Matrix solver failed.\n");

  // Output solution and the boundary condition.
  if (solution_output) 
  {
    out_fn_vtk(&sln, "sln");
    out_bc_vtk(&mesh, "bc");
  }

  // Time measurement.
  cpu_time.tick();

  // Print timing information.
  info("Solution and the boundary condition saved. Total running time: %g s", cpu_time.accumulated());

  // Clean up.
  delete matrix;
  delete rhs;
  delete solver;

  // Properly terminate the solver in the case of SOLVER_PETSC or SOLVER_MUMPS.
  finalize_solution_environment(matrix_solver);

  return 0;
}
Esempio n. 7
0
int main(int argc, char **args)
{
    // Test variable.
    int success_test = 1;

    // Load the initial mesh.
    Mesh mesh;
    H3DReader mesh_loader;
    mesh_loader.load("../hexahedron.mesh3d", &mesh);

    // Perform initial mesh refinement.
    for (int i=0; i < INIT_REF_NUM; i++) mesh.refine_all_elements(H3D_H3D_H3D_REFT_HEX_XYZ);

    // Create H1 space with default shapeset.
    H1Space space(&mesh, bc_types, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));

    // Construct initial solution and set it to zero.
    Solution sln_prev(&mesh);
    sln_prev.set_zero();

    // Initialize weak formulation.
    WeakForm wf;
    wf.add_matrix_form(bilinear_form<double, scalar>, bilinear_form<Ord, Ord>, HERMES_SYM);
    wf.add_vector_form(linear_form<double, scalar>, linear_form<Ord, Ord>, HERMES_ANY_INT, &sln_prev);

    // Initialize discrete problem.
    bool is_linear = true;
    DiscreteProblem dp(&wf, &space, is_linear);

    // Set up the solver, matrix, and rhs according to the solver selection.
    SparseMatrix* matrix = create_matrix(matrix_solver);
    Vector* rhs = create_vector(matrix_solver);
    Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);

    // Initialize the preconditioner in the case of SOLVER_AZTECOO.
    if (matrix_solver == SOLVER_AZTECOO)
    {
        ((AztecOOSolver*) solver)->set_solver(iterative_method);
        ((AztecOOSolver*) solver)->set_precond(preconditioner);
        // Using default iteration parameters (see solver/aztecoo.h).
    }

    // Exact error for testing purposes.
    double err_exact;

    // Time stepping.
    int nsteps = (int) (FINAL_TIME/TAU + 0.5);
    for (int ts = 0; ts < nsteps;  ts++)
    {
        info("---- Time step %d, time %3.5f.", ts, TIME);

        // Assemble the linear problem.
        info("Assembling the linear problem (ndof: %d).", Space::get_num_dofs(&space));

        if (ts == 0) dp.assemble(matrix, rhs);
        else dp.assemble(NULL, rhs);

        // Solve the linear system. If successful, obtain the solution.
        info("Solving the linear problem.");
        Solution sln(space.get_mesh());
        if(solver->solve()) Solution::vector_to_solution(solver->get_solution(), &space, &sln);
        else error ("Matrix solver failed.\n");

        // Output solution.
        if (solution_output)
            out_fn_vtk(&sln, "sln", ts);


        // Calculate exact error.
        ExactSolution esln(&mesh, fndd);

        info("Calculating exact error.");
        Adapt *adaptivity = new Adapt(&space, HERMES_H1_NORM);
        bool solutions_for_adapt = false;
        err_exact = adaptivity->calc_err_exact(&sln, &esln, solutions_for_adapt, HERMES_TOTAL_ERROR_ABS) * 100;
        info("Err. exact: %g%%.", err_exact);

        // Next time step.
        sln_prev = sln;
        TIME += TAU;

        // Cleanup.
        delete adaptivity;
    }

    if(err_exact > 3.00)
        success_test = 0;

    // Clean up.
    delete matrix;
    delete rhs;
    delete solver;

    if (success_test) {
        info("Success!");
        return ERR_SUCCESS;
    }
    else {
        info("Failure!");
        return ERR_FAILURE;
    }
}
Esempio n. 8
0
int main(int argc, char **args)
{
	int res = ERR_SUCCESS;

#ifdef WITH_PETSC
	PetscInitialize(&argc, &args, (char *) PETSC_NULL, PETSC_NULL);
#endif

	if (argc < 2) error("Not enough parameters.");

	printf("* Loading mesh '%s'\n", args[1]);
	Mesh mesh1;
	H3DReader mesh_loader;
	if (!mesh_loader.load(args[1], &mesh1)) error("Loading mesh file '%s'\n", args[1]);

#if defined RHS2

	Ord3 order(P_INIT_X, P_INIT_Y, P_INIT_Z);
	printf("  - Setting uniform order to (%d, %d, %d)\n", order.x, order.y, order.z);
	
	// Create an H1 space with default shapeset.
	printf("* Setting the space up\n");
	H1Space space(&mesh1, bc_types, essential_bc_values, order);

	int ndofs = space.assign_dofs();
	printf("  - Number of DOFs: %d\n", ndofs);

	printf("* Calculating a solution\n");

	// duplicate the mesh
	Mesh mesh2;
	mesh2.copy(mesh1);
	// do some changes
	mesh2.refine_all_elements(H3D_H3D_H3D_REFT_HEX_XYZ);
	mesh2.refine_all_elements(H3D_H3D_H3D_REFT_HEX_XYZ);

	Solution fsln(&mesh2);
	fsln.set_const(-6.0);
#else
	// duplicate the mesh
	Mesh mesh2;
	mesh2.copy(mesh1);

	Mesh mesh3;
	mesh3.copy(mesh1);

	// change meshes
	mesh1.refine_all_elements(H3D_REFT_HEX_X);
	mesh2.refine_all_elements(H3D_REFT_HEX_Y);
	mesh3.refine_all_elements(H3D_REFT_HEX_Z);

	printf("* Setup spaces\n");
	Ord3 o1(2, 2, 2);
	printf("  - Setting uniform order to (%d, %d, %d)\n", o1.x, o1.y, o1.z);
	H1Space space1(&mesh1, bc_types_1, essential_bc_values_1, o1);

	Ord3 o2(2, 2, 2);
	printf("  - Setting uniform order to (%d, %d, %d)\n", o2.x, o2.y, o2.z);
	H1Space space2(&mesh2, bc_types_2, essential_bc_values_2, o2);

	Ord3 o3(1, 1, 1);
	printf("  - Setting uniform order to (%d, %d, %d)\n", o3.x, o3.y, o3.z);
	H1Space space3(&mesh3, bc_types_3, essential_bc_values_3, o3);

	int ndofs = 0;
	ndofs += space1.assign_dofs();
	ndofs += space2.assign_dofs(ndofs);
	ndofs += space3.assign_dofs(ndofs);
	printf("  - Number of DOFs: %d\n", ndofs);
#endif

#if defined WITH_UMFPACK
	MatrixSolverType matrix_solver = SOLVER_UMFPACK; 
#elif defined WITH_PETSC
	MatrixSolverType matrix_solver = SOLVER_PETSC; 
#elif defined WITH_MUMPS
	MatrixSolverType matrix_solver = SOLVER_MUMPS; 
#endif

#ifdef RHS2
	WeakForm wf;
	wf.add_matrix_form(bilinear_form<double, scalar>, bilinear_form<Ord, Ord>, HERMES_SYM);
	wf.add_vector_form(linear_form<double, scalar>, linear_form<Ord, Ord>, HERMES_ANY_INT, &fsln);

	// Initialize discrete problem.
	bool is_linear = true;
	DiscreteProblem dp(&wf, &space, is_linear);
#elif defined SYS3
	WeakForm wf(3);
	wf.add_matrix_form(0, 0, biform_1_1<double, scalar>, biform_1_1<Ord, Ord>, HERMES_SYM);
	wf.add_matrix_form(0, 1, biform_1_2<double, scalar>, biform_1_2<Ord, Ord>, HERMES_NONSYM);
	wf.add_vector_form(0, liform_1<double, scalar>, liform_1<Ord, Ord>);

	wf.add_matrix_form(1, 1, biform_2_2<double, scalar>, biform_2_2<Ord, Ord>, HERMES_SYM);
	wf.add_matrix_form(1, 2, biform_2_3<double, scalar>, biform_2_3<Ord, Ord>, HERMES_NONSYM);
	wf.add_vector_form(1, liform_2<double, scalar>, liform_2<Ord, Ord>);

	wf.add_matrix_form(2, 2, biform_3_3<double, scalar>, biform_3_3<Ord, Ord>, HERMES_SYM);

	// Initialize discrete problem.
	bool is_linear = true;
	DiscreteProblem dp(&wf, Hermes::vector<Space *>(&space1, &space2, &space3), is_linear);
#endif
	// Time measurement.
	TimePeriod cpu_time;
	cpu_time.tick();
  
	// Set up the solver, matrix, and rhs according to the solver selection.
	SparseMatrix* matrix = create_matrix(matrix_solver);
	Vector* rhs = create_vector(matrix_solver);
	Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);

	// Initialize the preconditioner in the case of SOLVER_AZTECOO.
	if (matrix_solver == SOLVER_AZTECOO) 
	{
		((AztecOOSolver*) solver)->set_solver(iterative_method);
		((AztecOOSolver*) solver)->set_precond(preconditioner);
		// Using default iteration parameters (see solver/aztecoo.h).
	}

	// Assemble stiffness matrix and load vector.
	dp.assemble(matrix, rhs);

	// Solve the linear system. If successful, obtain the solution.
	info("Solving the linear problem.");
	bool solved = solver->solve();

	// Time measurement.
	cpu_time.tick();
	// Print timing information.
	info("Solution and mesh with polynomial orders saved. Total running time: %g s", cpu_time.accumulated());

	// Time measurement.
	TimePeriod sln_time;
	sln_time.tick();

	if (solved) {
#ifdef RHS2
		// Solve the linear system. If successful, obtain the solution.
		info("Solving the linear problem.");
                Solution sln(&mesh1);
		Solution::vector_to_solution(solver->get_solution(), &space, &sln);

		// Set exact solution.
		ExactSolution ex_sln(&mesh1, exact_solution);

		// Norm.
		double h1_sln_norm = h1_norm(&sln);
		double h1_err_norm = h1_error(&sln, &ex_sln);
		printf("  - H1 solution norm:   % le\n", h1_sln_norm);
		printf("  - H1 error norm:      % le\n", h1_err_norm);

		double l2_sln_norm = l2_norm(&sln);
		double l2_err_norm = l2_error(&sln, &ex_sln);
		printf("  - L2 solution norm:   % le\n", l2_sln_norm);
		printf("  - L2 error norm:      % le\n", l2_err_norm);

		if (h1_err_norm > EPS || l2_err_norm > EPS) {
			// Calculated solution is not enough precise.
			res = ERR_FAILURE;
		}
#elif defined SYS3
		// Solution 1.
		Solution sln1(&mesh1);
		Solution sln2(&mesh2);
		Solution sln3(&mesh3);

		Solution::vector_to_solution(solver->get_solution(), &space1, &sln1);
		Solution::vector_to_solution(solver->get_solution(), &space2, &sln2);
		Solution::vector_to_solution(solver->get_solution(), &space3, &sln3);

		ExactSolution esln1(&mesh1, exact_sln_fn_1);
		ExactSolution esln2(&mesh2, exact_sln_fn_2);
		ExactSolution esln3(&mesh3, exact_sln_fn_3);

		// Norm.
		double h1_err_norm1 = h1_error(&sln1, &esln1);
		double h1_err_norm2 = h1_error(&sln2, &esln2);
		double h1_err_norm3 = h1_error(&sln3, &esln3);

		double l2_err_norm1 = l2_error(&sln1, &esln1);
		double l2_err_norm2 = l2_error(&sln2, &esln2);
		double l2_err_norm3 = l2_error(&sln3, &esln3);

		printf("  - H1 error norm:      % le\n", h1_err_norm1);
		printf("  - L2 error norm:      % le\n", l2_err_norm1);
		if (h1_err_norm1 > EPS || l2_err_norm1 > EPS) {
			// Calculated solution is not enough precise.
			res = ERR_FAILURE;
		}

		printf("  - H1 error norm:      % le\n", h1_err_norm2);
		printf("  - L2 error norm:      % le\n", l2_err_norm2);
		if (h1_err_norm2 > EPS || l2_err_norm2 > EPS) {
			// Calculated solution is not enough precise.
			res = ERR_FAILURE;
		}

		printf("  - H1 error norm:      % le\n", h1_err_norm3);
		printf("  - L2 error norm:      % le\n", l2_err_norm3);
		if (h1_err_norm3 > EPS || l2_err_norm3 > EPS) {
			// Calculated solution is not enough precise.
			res = ERR_FAILURE;
		}
#endif

#ifdef RHS2
		out_fn_vtk(&sln, "solution");
#elif defined SYS3
		out_fn_vtk(&sln1, "sln1");
		out_fn_vtk(&sln2, "sln2");
		out_fn_vtk(&sln3, "sln3");
#endif
	}
	else
		res = ERR_FAILURE;

	// Print timing information.
	info("Solution and mesh with polynomial orders saved. Total running time: %g s", sln_time.accumulated());

	// Clean up.
	delete matrix;
	delete rhs;
	delete solver;

	return res;
}
Esempio n. 9
0
int main(int argc, char* argv[])
{
  info("Desired number of eigenvalues: %d.", NUMBER_OF_EIGENVALUES);

  // Load the mesh.
  info("Loading and refining mesh...");
  Mesh mesh;
  H3DReader mloader;
  mloader.load("hexahedron.mesh3d", &mesh);

  // Perform initial mesh refinements (optional).
  for (int i = 0; i < INIT_REF_NUM; i++) mesh.refine_all_elements(H3D_H3D_H3D_REFT_HEX_XYZ);

  // Create an H1 space with default shapeset.
  H1Space space(&mesh, bc_types, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));
  int ndof = Space::get_num_dofs(&space);
  info("ndof: %d.", ndof);

  // Initialize the weak formulation for the left hand side, i.e., H.
  info("Initializing weak form...");
  WeakForm wf_left, wf_right;
  wf_left.add_matrix_form(bilinear_form_left, bilinear_form_left_ord, HERMES_SYM, HERMES_ANY );
  wf_right.add_matrix_form(callback(bilinear_form_right), HERMES_SYM, HERMES_ANY );

  // Initialize matrices and matrix solver.
  SparseMatrix* matrix_left = create_matrix(matrix_solver);
  SparseMatrix* matrix_right = create_matrix(matrix_solver);
  Solver* solver = create_linear_solver(matrix_solver, matrix_left);

  // Assemble the matrices.
  info("Assembling matrices...");
  bool is_linear = true;
  DiscreteProblem dp_left(&wf_left, &space, is_linear);
  dp_left.assemble(matrix_left);
  DiscreteProblem dp_right(&wf_right, &space, is_linear);
  dp_right.assemble(matrix_right);

  // Write matrix_left in MatrixMarket format.
  write_matrix_mm("mat_left.mtx", matrix_left);

  // Write matrix_right in MatrixMarket format.
  write_matrix_mm("mat_right.mtx", matrix_right);

  // Calling Python eigensolver. Solution will be written to "eivecs.dat".
  info("Using eigensolver...");
  char call_cmd[255];
  sprintf(call_cmd, "python solveGenEigenFromMtx.py mat_left.mtx mat_right.mtx %g %d %g %d", 
	  TARGET_VALUE, NUMBER_OF_EIGENVALUES, TOL, MAX_ITER);
  system(call_cmd);

  // Initializing solution vector, solution and ScalarView.
  info("Initializing solution vector...");
  double* coeff_vec = new double[ndof];
  Solution sln(space.get_mesh());


  // Reading solution vectors from file and visualizing.
  info("Reading solution vectors from file and saving as solutions in paraview format...");
  FILE *file = fopen("eivecs.dat", "r");
  char line [64];                  // Maximum line size.
  fgets(line, sizeof line, file);  // ndof
  int n = atoi(line);            
  if (n != ndof) error("Mismatched ndof in the eigensolver output file.");  
  fgets(line, sizeof line, file);  // Number of eigenvectors in the file.
  int neig = atoi(line);
  if (neig != NUMBER_OF_EIGENVALUES) error("Mismatched number of eigenvectors in the eigensolver output file.");  
  for (int ieig = 0; ieig < neig; ieig++) {
    // Get next eigenvector from the file.
    for (int i = 0; i < ndof; i++) {  
      fgets(line, sizeof line, file);
      coeff_vec[i] = atof(line);
    }

    // Convert coefficient vector into a Solution.
    Solution::vector_to_solution(coeff_vec, &space, &sln);

    out_fn_vtk(&sln, "sln", ieig );
  }  
  fclose(file);

  delete [] coeff_vec;

  return 0; 
};
Esempio n. 10
0
int main(int argc, char **args) 
{
  // Time measurement.
  TimePeriod cpu_time;
  cpu_time.tick();

  // Load the mesh. 
  Mesh mesh;
  H3DReader mloader;
  mloader.load("lshape_hex.mesh3d", &mesh);

  // Perform initial mesh refinement.
  for (int i=0; i < INIT_REF_NUM; i++) mesh.refine_all_elements(H3D_H3D_H3D_REFT_HEX_XYZ);

  // Create an Hcurl space with default shapeset.
  HcurlSpace space(&mesh, bc_types, essential_bc_values, Ord3(P_INIT_X, P_INIT_Y, P_INIT_Z));

  // Initialize weak formulation.
  WeakForm wf;
  wf.add_matrix_form(biform<double, scalar>, biform<Ord, Ord>, HERMES_SYM);
  wf.add_matrix_form_surf(biform_surf, biform_surf_ord);
  wf.add_vector_form_surf(liform_surf, liform_surf_ord);

  // Initialize discrete problem.
  bool is_linear = true;
  DiscreteProblem dp(&wf, &space, is_linear);

  // Initialize the solver in the case of SOLVER_PETSC or SOLVER_MUMPS.
  initialize_solution_environment(matrix_solver, argc, args);
  
  // Set up the solver, matrix, and rhs according to the solver selection.
  SparseMatrix* matrix = create_matrix(matrix_solver);
  Vector* rhs = create_vector(matrix_solver);
  Solver* solver = create_linear_solver(matrix_solver, matrix, rhs);

  // Initialize the preconditioner in the case of SOLVER_AZTECOO.
  if (matrix_solver == SOLVER_AZTECOO) 
  {
    ((AztecOOSolver*) solver)->set_solver(iterative_method);
    ((AztecOOSolver*) solver)->set_precond(preconditioner);
    // Using default iteration parameters (see solver/aztecoo.h).
  }

  // Assemble stiffness matrix and load vector.
  info("Assembling the linear problem (ndof: %d).", Space::get_num_dofs(&space));
  dp.assemble(matrix, rhs);

  // Solve the linear system. If successful, obtain the solution.
  info("Solving the linear problem.");
  Solution sln(space.get_mesh());
  if(solver->solve()) Solution::vector_to_solution(solver->get_solution(), &space, &sln);
  else error ("Matrix solver failed.\n");

  // Output solution and mesh with polynomial orders.
  if (solution_output) 
  {
    out_fn_vtk(&sln, "sln");
    out_orders_vtk(&space, "order");
  }
  
  // Time measurement.
  cpu_time.tick();

  // Print timing information.
  info("Solution and mesh with polynomial orders saved. Total running time: %g s", cpu_time.accumulated());

  // Clean up.
  delete matrix;
  delete rhs;
  delete solver;

  // Properly terminate the solver in the case of SOLVER_PETSC or SOLVER_MUMPS.
  finalize_solution_environment(matrix_solver);

  return 0;
}