int main(int argc, char* argv[])
{
// Initialize Python
Py_Initialize();
PySys_SetArgv(argc, argv);
if (import_hermes2d___hermes2d())
throw std::runtime_error("hermes2d failed to import.");
cmd("import utils");
// load the mesh file
Mesh mesh;
mesh.load("domain-quad.mesh"); // unstructured triangular mesh available in domain-tri.mesh
// a-priori mesh refinements
mesh.refine_all_elements();
mesh.refine_towards_boundary(marker_obstacle, 4, false);
//mesh.refine_towards_boundary(marker_bottom, 4);
//mesh.refine_towards_boundary(marker_top, 4);
// plot the mesh:
//insert_object("mesh", Mesh_from_C(&mesh));
//cmd("mesh.plot(lib='mpl', method='orders')");
// display the mesh
//MeshView mview("Navier-Stokes Example - Mesh", 100, 100, 1100, 400);
//mview.show(&mesh);
//mview.wait_for_keypress();
// initialize the shapesets and the cache
H1ShapesetBeuchler shapeset_h1;
PrecalcShapeset pss_h1(&shapeset_h1);
L2Shapeset shapeset_l2;
PrecalcShapeset pss_l2(&shapeset_l2);
// H1 spaces for velocities and L2 for pressure
H1Space xvel(&mesh, &shapeset_h1);
H1Space yvel(&mesh, &shapeset_h1);
L2Space press(&mesh, &shapeset_l2);
// initialize boundary conditions
xvel.set_bc_types(xvel_bc_type);
xvel.set_bc_values(xvel_bc_value);
yvel.set_bc_types(yvel_bc_type);
press.set_bc_types(press_bc_type);
// set velocity and pressure polynomial degrees
xvel.set_uniform_order(P_INIT_VEL);
yvel.set_uniform_order(P_INIT_VEL);
press.set_uniform_order(P_INIT_PRESSURE);
// assign degrees of freedom
int ndofs = 0;
ndofs += xvel.assign_dofs(ndofs);
ndofs += yvel.assign_dofs(ndofs);
ndofs += press.assign_dofs(ndofs);
// initial BC: xprev and yprev are zero
xprev.set_zero(&mesh);
yprev.set_zero(&mesh);
// set up weak formulation
WeakForm wf(3);
wf.add_biform(0, 0, bilinear_form_sym_0_0_1_1, SYM);
wf.add_biform(0, 0, bilinear_form_unsym_0_0_1_1, UNSYM, ANY, 2, &xprev, &yprev);
wf.add_biform(1, 1, bilinear_form_sym_0_0_1_1, SYM);
wf.add_biform(1, 1, bilinear_form_unsym_0_0_1_1, UNSYM, ANY, 2, &xprev, &yprev);
wf.add_biform(0, 2, bilinear_form_unsym_0_2, ANTISYM);
wf.add_biform(1, 2, bilinear_form_unsym_1_2, ANTISYM);
wf.add_liform(0, linear_form_0, ANY, 1, &xprev);
wf.add_liform(1, linear_form_1, ANY, 1, &yprev);
// visualization
//VectorView vview("velocity [m/s]", 0, 0, 1500, 470);
//ScalarView pview("pressure [Pa]", 0, 530, 1500, 470);
//vview.set_min_max_range(0, 1.6);
//pview.show_mesh(false);
// fixing scale width (for nicer videos). Note: creation of videos is
// discussed in a separate example
//vview.fix_scale_width(5);
//pview.fix_scale_width(5);
// set up the linear system
DummySolver umfpack;
LinSystem sys(&wf, &umfpack);
sys.set_spaces(3, &xvel, &yvel, &press);
sys.set_pss(3, &pss_h1, &pss_h1, &pss_l2);
cmd("from hermes2d import Linearizer, Vectorizer");
cmd("from scipy.sparse import csc_matrix");
cmd("from scipy.sparse.linalg.dsolve import spsolve");
cmd("from scipy.sparse.linalg import cg");
// main loop
char title[100];
int num_time_steps = FINAL_TIME / TAU;
for (int i = 1; i <= num_time_steps; i++)
{
TIME += TAU;
info("\n---- Time step %d, time = %g -----------------------------------", i, TIME);
// this is needed to update the time-dependent boundary conditions
ndofs = 0;
ndofs += xvel.assign_dofs(ndofs);
ndofs += yvel.assign_dofs(ndofs);
ndofs += press.assign_dofs(ndofs);
// assemble and solve
Solution xsln, ysln, psln;
psln.set_zero(&mesh);
sys.assemble();
//sys.solve(3, &xsln, &ysln, &psln);
int *Ap, *Ai, n, nnz;
scalar *Ax;
sys.get_matrix(Ap, Ai, Ax, n);
nnz = Ap[n];
scalar *rhs;
sys.get_rhs(rhs, n);
insert_int_array("Ap", Ap, n+1);
insert_int_array("Ai", Ai, nnz);
insert_double_array("Ax", Ax, nnz);
insert_double_array("rhs", rhs, n);
cmd("A = csc_matrix((Ax, Ai, Ap))");
cmd("x = spsolve(A, rhs)");
double *X;
array_double_numpy2c_inplace(get_symbol("x"), &X, &n);
xsln.set_fe_solution(sys.get_space(0), sys.get_pss(0), X);
ysln.set_fe_solution(sys.get_space(1), sys.get_pss(1), X);
psln.set_fe_solution(sys.get_space(2), sys.get_pss(2), X);
insert_object("xsln", Solution_from_C(&xsln));
insert_object("ysln", Solution_from_C(&ysln));
insert_object("psln", Solution_from_C(&psln));
cmd("l = Linearizer()");
cmd("l.process_solution(psln)");
cmd("vert = l.get_vertices()");
cmd("triangles = l.get_triangles()");
cmd("utils.plot(vert, triangles)");
cmd("v = Vectorizer()");
cmd("v.process_solution(xsln, ysln)");
cmd("v_vert = v.get_vertices()");
cmd("v_triangles = v.get_triangles()");
cmd("utils.plot_vec(v_vert, v_triangles)");
//cmd("import IPython; IPython.ipapi.set_trace()");
// visualization
sprintf(title, "Velocity, time %g", TIME);
//vview.set_title(title);
//vview.show(&xprev, &yprev, EPS_LOW);
sprintf(title, "Pressure, time %g", TIME);
//pview.set_title(title);
//pview.show(&psln);
xprev = xsln;
yprev = ysln;
}
//View::wait();
}
int main(int argc, char* argv[])
{
// load the mesh file
Mesh mesh;
H2DReader mloader;
mloader.load("domain-quad.mesh", &mesh); // unstructured triangular mesh available in domain-tri.mesh
// a-priori mesh refinements
mesh.refine_all_elements();
mesh.refine_towards_boundary(5, 4, false);
mesh.refine_towards_boundary(1, 4);
mesh.refine_towards_boundary(3, 4);
// display the mesh
//MeshView mview("Navier-Stokes Example - Mesh", 100, 100, 1100, 400);
//mview.show(&mesh);
//mview.wait_for_keypress();
// initialize the shapesets and the cache
H1Shapeset shapeset_h1;
PrecalcShapeset pss_h1(&shapeset_h1);
L2Shapeset shapeset_l2;
PrecalcShapeset pss_l2(&shapeset_l2);
// H1 spaces for velocities and L2 for pressure
H1Space xvel(&mesh, &shapeset_h1);
H1Space yvel(&mesh, &shapeset_h1);
L2Space press(&mesh, &shapeset_l2);
// initialize boundary conditions
xvel.set_bc_types(xvel_bc_type);
xvel.set_bc_values(xvel_bc_value);
yvel.set_bc_types(yvel_bc_type);
press.set_bc_types(press_bc_type);
// set velocity and pressure polynomial degrees
xvel.set_uniform_order(P_INIT_VEL);
yvel.set_uniform_order(P_INIT_VEL);
press.set_uniform_order(P_INIT_PRESSURE);
// assign degrees of freedom
int ndofs = 0;
ndofs += xvel.assign_dofs(ndofs);
ndofs += yvel.assign_dofs(ndofs);
ndofs += press.assign_dofs(ndofs);
// initial condition: xprev and yprev are zero
Solution xprev, yprev;
xprev.set_zero(&mesh);
yprev.set_zero(&mesh);
// set up weak formulation
WeakForm wf(3);
wf.add_biform(0, 0, callback(bilinear_form_sym_0_0_1_1), SYM);
wf.add_biform(0, 0, callback(bilinear_form_unsym_0_0_1_1), UNSYM, ANY, 2, &xprev, &yprev);
wf.add_biform(1, 1, callback(bilinear_form_sym_0_0_1_1), SYM);
wf.add_biform(1, 1, callback(bilinear_form_unsym_0_0_1_1), UNSYM, ANY, 2, &xprev, &yprev);
wf.add_biform(0, 2, callback(bilinear_form_unsym_0_2), ANTISYM);
wf.add_biform(1, 2, callback(bilinear_form_unsym_1_2), ANTISYM);
wf.add_liform(0, callback(linear_form), ANY, 1, &xprev);
wf.add_liform(1, callback(linear_form), ANY, 1, &yprev);
// visualization
VectorView vview("velocity [m/s]", 0, 0, 1500, 470);
ScalarView pview("pressure [Pa]", 0, 530, 1500, 470);
vview.set_min_max_range(0, 1.6);
vview.fix_scale_width(80);
pview.show_mesh(false);
pview.fix_scale_width(80);
// fixing scale width (for nicer videos). Note: creation of videos is
// discussed in a separate example
vview.fix_scale_width(5);
pview.fix_scale_width(5);
// set up the linear system
UmfpackSolver umfpack;
LinSystem sys(&wf, &umfpack);
sys.set_spaces(3, &xvel, &yvel, &press);
sys.set_pss(3, &pss_h1, &pss_h1, &pss_l2);
// main loop
char title[100];
int num_time_steps = FINAL_TIME / TAU;
for (int i = 1; i <= num_time_steps; i++)
{
TIME += TAU;
info("\n---- Time step %d, time = %g -----------------------------------", i, TIME);
// this is needed to update the time-dependent boundary conditions
ndofs = 0;
ndofs += xvel.assign_dofs(ndofs);
ndofs += yvel.assign_dofs(ndofs);
ndofs += press.assign_dofs(ndofs);
// assemble and solve
Solution xsln, ysln, psln;
sys.assemble();
sys.solve(3, &xsln, &ysln, &psln);
// visualization
sprintf(title, "Velocity, time %g", TIME);
vview.set_title(title);
vview.show(&xprev, &yprev, EPS_LOW);
sprintf(title, "Pressure, time %g", TIME);
pview.set_title(title);
pview.show(&psln);
xprev = xsln;
yprev = ysln;
}
// wait for keyboard or mouse input
View::wait("Waiting for all views to be closed.");
return 0;
}