int main(int argc, char* argv[])
{
// Instantiate a class with global functions.
// Choose a Butcher's table or define your own.
ButcherTable bt(butcher_table_type);
if (bt.is_explicit()) info("Using a %d-stage explicit R-K method.", bt.get_size());
if (bt.is_diagonally_implicit()) info("Using a %d-stage diagonally implicit R-K method.", bt.get_size());
if (bt.is_fully_implicit()) info("Using a %d-stage fully implicit R-K method.", bt.get_size());
// Turn off adaptive time stepping if R-K method is not embedded.
if (bt.is_embedded() == false && ADAPTIVE_TIME_STEP_ON == true) {
warn("R-K method not embedded, turning off adaptive time stepping.");
ADAPTIVE_TIME_STEP_ON = false;
}
// Load the mesh.
Mesh mesh, basemesh;
MeshReaderH2D mloader;
mloader.load("square.mesh", &basemesh);
mesh.copy(&basemesh);
// Initial mesh refinements.
for(int i = 0; i < INIT_REF_NUM; i++) mesh.refine_all_elements();
// Convert initial condition into a Solution<std::complex<double> >.
CustomInitialCondition psi_time_prev(&mesh);
// Initialize the weak formulation.
double current_time = 0;
CustomWeakFormGPRK wf(h, m, g, omega);
// Initialize boundary conditions.
DefaultEssentialBCConst<std::complex<double> > bc_essential("Bdy", 0.0);
EssentialBCs<std::complex<double> > bcs(&bc_essential);
// Create an H1 space with default shapeset.
H1Space<std::complex<double> > space(&mesh, &bcs, P_INIT);
int ndof = space.get_num_dofs();
info("ndof = %d", ndof);
// Initialize the FE problem.
DiscreteProblem<std::complex<double> > dp(&wf, &space);
// Create a refinement selector.
H1ProjBasedSelector<std::complex<double> > selector(CAND_LIST, CONV_EXP, H2DRS_DEFAULT_ORDER);
// Visualize initial condition.
char title[100];
ScalarView sview_real("Initial condition - real part", new WinGeom(0, 0, 600, 500));
ScalarView sview_imag("Initial condition - imaginary part", new WinGeom(610, 0, 600, 500));
sview_real.show_mesh(false);
sview_imag.show_mesh(false);
sview_real.fix_scale_width(50);
sview_imag.fix_scale_width(50);
OrderView ord_view("Initial mesh", new WinGeom(445, 0, 440, 350));
ord_view.fix_scale_width(50);
ScalarView time_error_view("Temporal error", new WinGeom(0, 400, 440, 350));
time_error_view.fix_scale_width(50);
time_error_view.fix_scale_width(60);
ScalarView space_error_view("Spatial error", new WinGeom(445, 400, 440, 350));
space_error_view.fix_scale_width(50);
RealFilter real(&psi_time_prev);
ImagFilter imag(&psi_time_prev);
sview_real.show(&real);
sview_imag.show(&imag);
ord_view.show(&space);
// Graph for time step history.
SimpleGraph time_step_graph;
if (ADAPTIVE_TIME_STEP_ON) info("Time step history will be saved to file time_step_history.dat.");
// Time stepping:
int num_time_steps = (int)(T_FINAL/time_step + 0.5);
for(int ts = 1; ts <= num_time_steps; ts++)
// Time stepping loop.
double current_time = 0.0; int ts = 1;
do
{
info("Begin time step %d.", ts);
// Periodic global derefinement.
if (ts > 1 && ts % UNREF_FREQ == 0)
{
info("Global mesh derefinement.");
switch (UNREF_METHOD) {
case 1: mesh.copy(&basemesh);
space.set_uniform_order(P_INIT);
break;
case 2: mesh.unrefine_all_elements();
space.set_uniform_order(P_INIT);
break;
case 3: mesh.unrefine_all_elements();
//space.adjust_element_order(-1, P_INIT);
space.adjust_element_order(-1, -1, P_INIT, P_INIT);
break;
default: error("Wrong global derefinement method.");
}
ndof = Space<std::complex<double> >::get_num_dofs(&space);
}
info("ndof: %d", ndof);
// Spatial adaptivity loop. Note: psi_time_prev must not be
// changed during spatial adaptivity.
Solution<std::complex<double> > ref_sln;
Solution<std::complex<double> >* time_error_fn;
if (bt.is_embedded() == true) time_error_fn = new Solution<std::complex<double> >(&mesh);
else time_error_fn = NULL;
bool done = false; int as = 1;
double err_est;
do {
// Construct globally refined reference mesh and setup reference space.
Space<std::complex<double> >* ref_space = Space<std::complex<double> >::construct_refined_space(&space);
// Initialize discrete problem on reference mesh.
DiscreteProblem<std::complex<double> >* ref_dp = new DiscreteProblem<std::complex<double> >(&wf, ref_space);
RungeKutta<std::complex<double> > runge_kutta(ref_dp, &bt, matrix_solver_type);
// Runge-Kutta step on the fine mesh.
info("Runge-Kutta time step on fine mesh (t = %g s, time step = %g s, stages: %d).",
current_time, time_step, bt.get_size());
bool verbose = true;
try
{
runge_kutta.rk_time_step_newton(current_time, time_step, &psi_time_prev,
&ref_sln, time_error_fn, false, false, verbose,
NEWTON_TOL_FINE, NEWTON_MAX_ITER);
}
catch(Exceptions::Exception& e)
{
e.printMsg();
error("Runge-Kutta time step failed");
}
/* If ADAPTIVE_TIME_STEP_ON == true, estimate temporal error.
If too large or too small, then adjust it and restart the time step. */
double rel_err_time = 0;
if (bt.is_embedded() == true) {
info("Calculating temporal error estimate.");
// Show temporal error.
char title[100];
sprintf(title, "Temporal error est, spatial adaptivity step %d", as);
time_error_view.set_title(title);
time_error_view.show_mesh(false);
RealFilter abs_time(time_error_fn);
AbsFilter abs_tef(&abs_time);
time_error_view.show(&abs_tef, HERMES_EPS_HIGH);
rel_err_time = Global<std::complex<double> >::calc_norm(time_error_fn, HERMES_H1_NORM) /
Global<std::complex<double> >::calc_norm(&ref_sln, HERMES_H1_NORM) * 100;
if (ADAPTIVE_TIME_STEP_ON == false) info("rel_err_time: %g%%", rel_err_time);
}
if (ADAPTIVE_TIME_STEP_ON) {
if (rel_err_time > TIME_ERR_TOL_UPPER) {
info("rel_err_time %g%% is above upper limit %g%%", rel_err_time, TIME_ERR_TOL_UPPER);
info("Decreasing time step from %g to %g s and restarting time step.",
time_step, time_step * TIME_STEP_DEC_RATIO);
time_step *= TIME_STEP_DEC_RATIO;
delete ref_space;
delete ref_dp;
continue;
}
else if (rel_err_time < TIME_ERR_TOL_LOWER) {
info("rel_err_time = %g%% is below lower limit %g%%", rel_err_time, TIME_ERR_TOL_LOWER);
info("Increasing time step from %g to %g s.", time_step, time_step * TIME_STEP_INC_RATIO);
time_step *= TIME_STEP_INC_RATIO;
delete ref_space;
delete ref_dp;
continue;
}
else {
info("rel_err_time = %g%% is in acceptable interval (%g%%, %g%%)",
rel_err_time, TIME_ERR_TOL_LOWER, TIME_ERR_TOL_UPPER);
}
// Add entry to time step history graph.
time_step_graph.add_values(current_time, time_step);
time_step_graph.save("time_step_history.dat");
}
/* Estimate spatial errors and perform mesh refinement */
info("Spatial adaptivity step %d.", as);
// Project the fine mesh solution onto the coarse mesh.
Solution<std::complex<double> > sln;
info("Projecting fine mesh solution on coarse mesh for error estimation.");
OGProjection<std::complex<double> >::project_global(&space, &ref_sln, &sln, matrix_solver_type);
// Show spatial error.
sprintf(title, "Spatial error est, spatial adaptivity step %d", as);
DiffFilter<std::complex<double> >* space_error_fn = new DiffFilter<std::complex<double> >(Hermes::vector<MeshFunction<std::complex<double> >*>(&ref_sln, &sln));
space_error_view.set_title(title);
space_error_view.show_mesh(false);
RealFilter abs_space(space_error_fn);
AbsFilter abs_sef(&abs_space);
space_error_view.show(&abs_sef);
// Calculate element errors and spatial error estimate.
info("Calculating spatial error estimate.");
Adapt<std::complex<double> >* adaptivity = new Adapt<std::complex<double> >(&space);
double err_rel_space = adaptivity->calc_err_est(&sln, &ref_sln) * 100;
// Report results.
info("ndof: %d, ref_ndof: %d, err_rel_space: %g%%",
Space<std::complex<double> >::get_num_dofs(&space), Space<std::complex<double> >::get_num_dofs(ref_space), err_rel_space);
// If err_est too large, adapt the mesh.
if (err_rel_space < SPACE_ERR_TOL) done = true;
else
{
info("Adapting the coarse mesh.");
done = adaptivity->adapt(&selector, THRESHOLD, STRATEGY, MESH_REGULARITY);
if (Space<std::complex<double> >::get_num_dofs(&space) >= NDOF_STOP)
done = true;
else
// Increase the counter of performed adaptivity steps.
as++;
}
// Clean up.
delete adaptivity;
delete ref_space;
delete ref_dp;
delete space_error_fn;
}
while (done == false);
// Clean up.
if (time_error_fn != NULL) delete time_error_fn;
// Visualize the solution and mesh.
char title[100];
sprintf(title, "Solution - real part, Time %3.2f s", current_time);
sview_real.set_title(title);
sprintf(title, "Solution - imaginary part, Time %3.2f s", current_time);
sview_imag.set_title(title);
RealFilter real(&ref_sln);
ImagFilter imag(&ref_sln);
sview_real.show(&real);
sview_imag.show(&imag);
sprintf(title, "Mesh, time %g s", current_time);
ord_view.set_title(title);
ord_view.show(&space);
// Copy last reference solution into psi_time_prev.
psi_time_prev.copy(&ref_sln);
// Increase current time and counter of time steps.
current_time += time_step;
ts++;
}
while (current_time < T_FINAL);
// Wait for all views to be closed.
View::wait();
return 0;
}
int main(int argc, char* argv[])
{
// Choose a Butcher's table or define your own.
ButcherTable bt(butcher_table_type);
if (bt.is_explicit()) Hermes::Mixins::Loggable::Static::info("Using a %d-stage explicit R-K method.", bt.get_size());
if (bt.is_diagonally_implicit()) Hermes::Mixins::Loggable::Static::info("Using a %d-stage diagonally implicit R-K method.", bt.get_size());
if (bt.is_fully_implicit()) Hermes::Mixins::Loggable::Static::info("Using a %d-stage fully implicit R-K method.", bt.get_size());
// Turn off adaptive time stepping if R-K method is not embedded.
if (bt.is_embedded() == false && ADAPTIVE_TIME_STEP_ON == true) {
Hermes::Mixins::Loggable::Static::warn("R-K method not embedded, turning off adaptive time stepping.");
ADAPTIVE_TIME_STEP_ON = false;
}
// Load the mesh.
MeshSharedPtr mesh(new Mesh), basemesh(new Mesh);
MeshReaderH2D mloader;
mloader.load("square.mesh", basemesh);
mesh->copy(basemesh);
// Initial mesh refinements.
for(int i = 0; i < INIT_REF_NUM; i++) mesh->refine_all_elements();
// Convert initial condition into a Solution<complex>.
MeshFunctionSharedPtr<complex> psi_time_prev(new CustomInitialCondition(mesh));
// Initialize the weak formulation.
double current_time = 0;
// Initialize weak formulation.
CustomWeakFormGPRK wf(h, m, g, omega);
// Initialize boundary conditions.
DefaultEssentialBCConst<complex> bc_essential("Bdy", 0.0);
EssentialBCs<complex> bcs(&bc_essential);
// Create an H1 space with default shapeset.
SpaceSharedPtr<complex> space(new H1Space<complex> (mesh, &bcs, P_INIT));
int ndof = space->get_num_dofs();
Hermes::Mixins::Loggable::Static::info("ndof = %d", ndof);
// Initialize the FE problem.
DiscreteProblem<complex> dp(&wf, space);
// Create a refinement selector.
H1ProjBasedSelector<complex> selector(CAND_LIST);
// Visualize initial condition.
char title[100];
ScalarView sview_real("Initial condition - real part", new WinGeom(0, 0, 600, 500));
ScalarView sview_imag("Initial condition - imaginary part", new WinGeom(610, 0, 600, 500));
sview_real.show_mesh(false);
sview_imag.show_mesh(false);
sview_real.fix_scale_width(50);
sview_imag.fix_scale_width(50);
OrderView ord_view("Initial mesh", new WinGeom(445, 0, 440, 350));
ord_view.fix_scale_width(50);
ScalarView time_error_view("Temporal error", new WinGeom(0, 400, 440, 350));
time_error_view.fix_scale_width(50);
time_error_view.fix_scale_width(60);
ScalarView space_error_view("Spatial error", new WinGeom(445, 400, 440, 350));
space_error_view.fix_scale_width(50);
MeshFunctionSharedPtr<double> real(new RealFilter(psi_time_prev));
MeshFunctionSharedPtr<double> imag(new ImagFilter(psi_time_prev));
sview_real.show(real);
sview_imag.show(imag);
ord_view.show(space);
// Graph for time step history.
SimpleGraph time_step_graph;
if (ADAPTIVE_TIME_STEP_ON) Hermes::Mixins::Loggable::Static::info("Time step history will be saved to file time_step_history.dat.");
// Time stepping:
int num_time_steps = (int)(T_FINAL/time_step + 0.5);
for(int ts = 1; ts <= num_time_steps; ts++)
// Time stepping loop.
double current_time = 0.0; int ts = 1;
do
{
Hermes::Mixins::Loggable::Static::info("Begin time step %d.", ts);
// Periodic global derefinement.
if (ts > 1 && ts % UNREF_FREQ == 0)
{
Hermes::Mixins::Loggable::Static::info("Global mesh derefinement.");
switch (UNREF_METHOD) {
case 1: mesh->copy(basemesh);
space->set_uniform_order(P_INIT);
break;
case 2: space->unrefine_all_mesh_elements();
space->set_uniform_order(P_INIT);
break;
case 3: space->unrefine_all_mesh_elements();
space->adjust_element_order(-1, -1, P_INIT, P_INIT);
break;
default: throw Hermes::Exceptions::Exception("Wrong global derefinement method.");
}
ndof = Space<complex>::get_num_dofs(space);
}
Hermes::Mixins::Loggable::Static::info("ndof: %d", ndof);
// Spatial adaptivity loop. Note: psi_time_prev must not be
// changed during spatial adaptivity.
MeshFunctionSharedPtr<complex> ref_sln(new Solution<complex>());
MeshFunctionSharedPtr<complex> time_error_fn(new Solution<complex>);
bool done = false;
int as = 1;
double err_est;
do {
// Construct globally refined reference mesh and setup reference space.
Mesh::ReferenceMeshCreator refMeshCreator(mesh);
MeshSharedPtr ref_mesh = refMeshCreator.create_ref_mesh();
Space<complex>::ReferenceSpaceCreator refSpaceCreator(space, ref_mesh);
SpaceSharedPtr<complex> ref_space = refSpaceCreator.create_ref_space();
// Initialize discrete problem on reference mesh.
DiscreteProblem<complex>* ref_dp = new DiscreteProblem<complex>(&wf, ref_space);
RungeKutta<complex> runge_kutta(&wf, ref_space, &bt);
// Runge-Kutta step on the fine mesh->
Hermes::Mixins::Loggable::Static::info("Runge-Kutta time step on fine mesh (t = %g s, time step = %g s, stages: %d).",
current_time, time_step, bt.get_size());
bool verbose = true;
try
{
runge_kutta.set_time(current_time);
runge_kutta.set_time_step(time_step);
runge_kutta.set_max_allowed_iterations(NEWTON_MAX_ITER);
runge_kutta.set_tolerance(NEWTON_TOL_FINE);
runge_kutta.rk_time_step_newton(psi_time_prev, ref_sln, time_error_fn);
}
catch(Exceptions::Exception& e)
{
e.print_msg();
throw Hermes::Exceptions::Exception("Runge-Kutta time step failed");
}
/* If ADAPTIVE_TIME_STEP_ON == true, estimate temporal error.
If too large or too small, then adjust it and restart the time step. */
double rel_err_time = 0;
if (bt.is_embedded() == true) {
Hermes::Mixins::Loggable::Static::info("Calculating temporal error estimate.");
// Show temporal error.
char title[100];
sprintf(title, "Temporal error est, spatial adaptivity step %d", as);
time_error_view.set_title(title);
time_error_view.show_mesh(false);
MeshFunctionSharedPtr<double> abs_time(new RealFilter(time_error_fn));
MeshFunctionSharedPtr<double> abs_tef(new AbsFilter(abs_time));
time_error_view.show(abs_tef);
rel_err_time = Global<complex>::calc_norm(time_error_fn.get(), HERMES_H1_NORM) /
Global<complex>::calc_norm(ref_sln.get(), HERMES_H1_NORM) * 100;
if (ADAPTIVE_TIME_STEP_ON == false) Hermes::Mixins::Loggable::Static::info("rel_err_time: %g%%", rel_err_time);
}
if (ADAPTIVE_TIME_STEP_ON) {
if (rel_err_time > TIME_ERR_TOL_UPPER) {
Hermes::Mixins::Loggable::Static::info("rel_err_time %g%% is above upper limit %g%%", rel_err_time, TIME_ERR_TOL_UPPER);
Hermes::Mixins::Loggable::Static::info("Decreasing time step from %g to %g s and restarting time step.",
time_step, time_step * TIME_STEP_DEC_RATIO);
time_step *= TIME_STEP_DEC_RATIO;
delete ref_dp;
continue;
}
else if (rel_err_time < TIME_ERR_TOL_LOWER) {
Hermes::Mixins::Loggable::Static::info("rel_err_time = %g%% is below lower limit %g%%", rel_err_time, TIME_ERR_TOL_LOWER);
Hermes::Mixins::Loggable::Static::info("Increasing time step from %g to %g s.", time_step, time_step * TIME_STEP_INC_RATIO);
time_step *= TIME_STEP_INC_RATIO;
delete ref_dp;
continue;
}
else {
Hermes::Mixins::Loggable::Static::info("rel_err_time = %g%% is in acceptable interval (%g%%, %g%%)",
rel_err_time, TIME_ERR_TOL_LOWER, TIME_ERR_TOL_UPPER);
}
// Add entry to time step history graph.
time_step_graph.add_values(current_time, time_step);
time_step_graph.save("time_step_history.dat");
}
/* Estimate spatial errors and perform mesh refinement */
Hermes::Mixins::Loggable::Static::info("Spatial adaptivity step %d.", as);
// Project the fine mesh solution onto the coarse mesh.
MeshFunctionSharedPtr<complex> sln(new Solution<complex>);
Hermes::Mixins::Loggable::Static::info("Projecting fine mesh solution on coarse mesh for error estimation.");
OGProjection<complex> ogProjection; ogProjection.project_global(space, ref_sln, sln);
// Show spatial error.
sprintf(title, "Spatial error est, spatial adaptivity step %d", as);
MeshFunctionSharedPtr<complex> space_error_fn(new DiffFilter<complex>(Hermes::vector<MeshFunctionSharedPtr<complex> >(ref_sln, sln)));
space_error_view.set_title(title);
space_error_view.show_mesh(false);
MeshFunctionSharedPtr<double> abs_space(new RealFilter(space_error_fn));
MeshFunctionSharedPtr<double> abs_sef(new AbsFilter(abs_space));
space_error_view.show(abs_sef);
// Calculate element errors and spatial error estimate.
Hermes::Mixins::Loggable::Static::info("Calculating spatial error estimate.");
Adapt<complex> adaptivity(space);
double err_rel_space = errorCalculator.get_total_error_squared() * 100;
// Report results.
Hermes::Mixins::Loggable::Static::info("ndof: %d, ref_ndof: %d, err_rel_space: %g%%",
Space<complex>::get_num_dofs(space), Space<complex>::get_num_dofs(ref_space), err_rel_space);
// If err_est too large, adapt the mesh.
if (err_rel_space < SPACE_ERR_TOL) done = true;
else
{
Hermes::Mixins::Loggable::Static::info("Adapting the coarse mesh.");
done = adaptivity.adapt(&selector);
// Increase the counter of performed adaptivity steps.
as++;
}
// Clean up.
delete ref_dp;
}
while (done == false);
// Visualize the solution and mesh->
char title[100];
sprintf(title, "Solution - real part, Time %3.2f s", current_time);
sview_real.set_title(title);
sprintf(title, "Solution - imaginary part, Time %3.2f s", current_time);
sview_imag.set_title(title);
MeshFunctionSharedPtr<double> real(new RealFilter(ref_sln));
MeshFunctionSharedPtr<double> imag(new ImagFilter(ref_sln));
sview_real.show(real);
sview_imag.show(imag);
sprintf(title, "Mesh, time %g s", current_time);
ord_view.set_title(title);
ord_view.show(space);
// Copy last reference solution into psi_time_prev.
psi_time_prev->copy(ref_sln);
// Increase current time and counter of time steps.
current_time += time_step;
ts++;
}
while (current_time < T_FINAL);
// Wait for all views to be closed.
View::wait();
return 0;
}
int main(int argc, char* argv[])
{
// Choose a Butcher's table or define your own.
ButcherTable bt(butcher_table_type);
if (bt.is_explicit()) info("Using a %d-stage explicit R-K method.", bt.get_size());
if (bt.is_diagonally_implicit()) info("Using a %d-stage diagonally implicit R-K method.", bt.get_size());
if (bt.is_fully_implicit()) info("Using a %d-stage fully implicit R-K method.", bt.get_size());
// Load the mesh.
Mesh mesh;
H2DReader mloader;
mloader.load("wall.mesh", &mesh);
// Perform initial mesh refinements.
for(int i = 0; i < INIT_REF_NUM; i++) mesh.refine_all_elements();
mesh.refine_towards_boundary(BDY_BOTTOM, INIT_REF_NUM_BDY);
// Enter boundary markers.
BCTypes bc_types;
bc_types.add_bc_neumann(Hermes::vector<int>(BDY_RIGHT, BDY_LEFT));
bc_types.add_bc_newton(Hermes::vector<int>(BDY_BOTTOM, BDY_TOP));
// Initialize an H1 space with default shapeset.
H1Space space(&mesh, &bc_types, NULL, P_INIT);
int ndof = Space::get_num_dofs(&space);
info("ndof = %d.", ndof);
// Previous and next time level solutions.
Solution* sln_time_prev = new Solution(&mesh, TEMP_INIT);
Solution* sln_time_new = new Solution(&mesh);
Solution* time_error_fn = new Solution(&mesh, 0.0);
// Initialize weak formulation.
WeakForm wf;
wf.add_matrix_form(stac_jacobian_vol, stac_jacobian_vol_ord, HERMES_NONSYM, HERMES_ANY, sln_time_prev);
wf.add_vector_form(stac_residual_vol, stac_residual_vol_ord, HERMES_ANY, sln_time_prev);
wf.add_matrix_form_surf(stac_jacobian_bottom, stac_jacobian_bottom_ord, BDY_BOTTOM, sln_time_prev);
wf.add_vector_form_surf(stac_residual_bottom, stac_residual_bottom_ord, BDY_BOTTOM, sln_time_prev);
wf.add_matrix_form_surf(stac_jacobian_top, stac_jacobian_top_ord, BDY_TOP, sln_time_prev);
wf.add_vector_form_surf(stac_residual_top, stac_residual_top_ord, BDY_TOP, sln_time_prev);
// Initialize the FE problem.
bool is_linear = true;
DiscreteProblem dp(&wf, &space, is_linear);
// Initialize views.
ScalarView Tview("Temperature", new WinGeom(0, 0, 1500, 400));
Tview.fix_scale_width(40);
ScalarView eview("Temporal error", new WinGeom(0, 450, 1500, 400));
eview.fix_scale_width(40);
// Graph for time step history.
SimpleGraph time_step_graph;
info("Time step history will be saved to file time_step_history.dat.");
// Time stepping loop:
double current_time = 0; int ts = 1;
do
{
// Perform one Runge-Kutta time step according to the selected Butcher's table.
info("Runge-Kutta time step (t = %g s, tau = %g s, stages: %d).",
current_time, time_step, bt.get_size());
bool verbose = true;
bool is_linear = true;
if (!rk_time_step(current_time, time_step, &bt, sln_time_prev, sln_time_new, time_error_fn, &dp, matrix_solver,
verbose, is_linear)) {
error("Runge-Kutta time step failed, try to decrease time step size.");
}
// Plot error function.
char title[100];
sprintf(title, "Temporal error, t = %g", current_time);
eview.set_title(title);
AbsFilter abs_tef(time_error_fn);
eview.show(&abs_tef, HERMES_EPS_VERYHIGH);
// Calculate relative time stepping error and decide whether the
// time step can be accepted. If not, then the time step size is
// reduced and the entire time step repeated. If yes, then another
// check is run, and if the relative error is very low, time step
// is increased.
double rel_err_time = calc_norm(time_error_fn, HERMES_H1_NORM) / calc_norm(sln_time_new, HERMES_H1_NORM) * 100;
info("rel_err_time = %g%%", rel_err_time);
if (rel_err_time > TIME_TOL_UPPER) {
info("rel_err_time above upper limit %g%% -> decreasing time step from %g to %g and restarting time step.",
TIME_TOL_UPPER, time_step, time_step * TIME_STEP_DEC_RATIO);
time_step *= TIME_STEP_DEC_RATIO;
continue;
}
if (rel_err_time < TIME_TOL_LOWER) {
info("rel_err_time = below lower limit %g%% -> increasing time step from %g to %g",
TIME_TOL_UPPER, time_step, time_step * TIME_STEP_INC_RATIO);
time_step *= TIME_STEP_INC_RATIO;
}
// Add entry to the timestep graph.
time_step_graph.add_values(current_time, time_step);
time_step_graph.save("time_step_history.dat");
// Update time.
current_time += time_step;
// Show the new time level solution.
sprintf(title, "Time %3.2f s", current_time);
Tview.set_title(title);
Tview.show(sln_time_new);
// Copy solution for the new time step.
sln_time_prev->copy(sln_time_new);
// Increase counter of time steps.
ts++;
}
while (current_time < T_FINAL);
// Cleanup.
delete sln_time_prev;
delete sln_time_new;
delete time_error_fn;
// Wait for the view to be closed.
View::wait();
return 0;
}
int main(int argc, char* argv[])
{
// Choose a Butcher's table or define your own.
ButcherTable bt(butcher_table_type);
if (bt.is_explicit()) info("Using a %d-stage explicit R-K method.", bt.get_size());
if (bt.is_diagonally_implicit()) info("Using a %d-stage diagonally implicit R-K method.", bt.get_size());
if (bt.is_fully_implicit()) info("Using a %d-stage fully implicit R-K method.", bt.get_size());
// Load the mesh.
Mesh mesh;
MeshReaderH2D mloader;
mloader.load("wall.mesh", &mesh);
// Perform initial mesh refinements.
for(int i = 0; i < INIT_REF_NUM; i++) mesh.refine_all_elements();
mesh.refine_towards_boundary(BDY_RIGHT, 2);
mesh.refine_towards_boundary(BDY_FIRE, INIT_REF_NUM_BDY);
// Initialize essential boundary conditions (none).
EssentialBCs<double> bcs;
// Initialize an H1 space with default shapeset.
H1Space<double> space(&mesh, &bcs, P_INIT);
int ndof = Space<double>::get_num_dofs(&space);
info("ndof = %d.", ndof);
// Previous and next time level solutions.
ConstantSolution<double> sln_time_prev(&mesh, TEMP_INIT);
ZeroSolution sln_time_new(&mesh);
ConstantSolution<double> time_error_fn(&mesh, 0.0);
// Initialize the weak formulation.
double current_time = 0;
CustomWeakFormHeatRK wf(BDY_FIRE, BDY_AIR, ALPHA_FIRE, ALPHA_AIR,
RHO, HEATCAP, TEMP_EXT_AIR, TEMP_INIT, ¤t_time);
// Initialize the FE problem.
DiscreteProblem<double> dp(&wf, &space);
// Initialize views.
ScalarView Tview("Temperature", new WinGeom(0, 0, 1500, 400));
Tview.fix_scale_width(40);
ScalarView eview("Temporal error", new WinGeom(0, 450, 1500, 400));
eview.fix_scale_width(40);
// Graph for time step history.
SimpleGraph time_step_graph;
info("Time step history will be saved to file time_step_history.dat.");
// Initialize Runge-Kutta time stepping.
RungeKutta<double> runge_kutta(&dp, &bt, matrix_solver_type);
// Time stepping loop:
int ts = 1;
do
{
// Perform one Runge-Kutta time step according to the selected Butcher's table.
info("Runge-Kutta time step (t = %g s, tau = %g s, stages: %d).",
current_time, time_step, bt.get_size());
bool jacobian_changed = false;
bool verbose = true;
try
{
runge_kutta.rk_time_step_newton(current_time, time_step, &sln_time_prev, &sln_time_new,
&time_error_fn, !jacobian_changed, false, verbose);
}
catch(Exceptions::Exception& e)
{
e.printMsg();
error("Runge-Kutta time step failed");
}
// Plot error function.
char title[100];
sprintf(title, "Temporal error, t = %g", current_time);
eview.set_title(title);
AbsFilter abs_tef(&time_error_fn);
eview.show(&abs_tef, HERMES_EPS_VERYHIGH);
// Calculate relative time stepping error and decide whether the
// time step can be accepted. If not, then the time step size is
// reduced and the entire time step repeated. If yes, then another
// check is run, and if the relative error is very low, time step
// is increased.
double rel_err_time = Global<double>::calc_norm(&time_error_fn, HERMES_H1_NORM)
/ Global<double>::calc_norm(&sln_time_new, HERMES_H1_NORM) * 100;
info("rel_err_time = %g%%", rel_err_time);
if (rel_err_time > TIME_TOL_UPPER) {
info("rel_err_time above upper limit %g%% -> decreasing time step from %g to %g and restarting time step.",
TIME_TOL_UPPER, time_step, time_step * TIME_STEP_DEC_RATIO);
time_step *= TIME_STEP_DEC_RATIO;
continue;
}
if (rel_err_time < TIME_TOL_LOWER) {
info("rel_err_time = below lower limit %g%% -> increasing time step from %g to %g",
TIME_TOL_UPPER, time_step, time_step * TIME_STEP_INC_RATIO);
time_step *= TIME_STEP_INC_RATIO;
}
// Add entry to the timestep graph.
time_step_graph.add_values(current_time, time_step);
time_step_graph.save("time_step_history.dat");
// Update time.
current_time += time_step;
// Show the new time level solution.
sprintf(title, "Time %3.2f s", current_time);
Tview.set_title(title);
Tview.show(&sln_time_new);
// Copy solution for the new time step.
sln_time_prev.copy(&sln_time_new);
// Increase counter of time steps.
ts++;
}
while (current_time < T_FINAL);
// Wait for the view to be closed.
View::wait();
return 0;
}