void testRestart() { SlitFunc slitfunc; _mesh->write("slit_mesh.xda"); _es->write("slit_solution.xda", EquationSystems::WRITE_DATA | EquationSystems::WRITE_SERIAL_FILES); Mesh mesh2(*TestCommWorld); mesh2.read("slit_mesh.xda"); EquationSystems es2(mesh2); es2.read("slit_solution.xda"); System & sys2 = es2.get_system<System> ("SimpleSystem"); unsigned int dim = 2; CPPUNIT_ASSERT_EQUAL( sys2.n_vars(), 1u ); FEMContext context(sys2); FEBase * fe = NULL; context.get_element_fe( 0, fe, dim ); const std::vector<Point> & xyz = fe->get_xyz(); fe->get_phi(); MeshBase::const_element_iterator el = mesh2.active_local_elements_begin(); const MeshBase::const_element_iterator end_el = mesh2.active_local_elements_end(); for (; el != end_el; ++el) { const Elem * elem = *el; context.pre_fe_reinit(sys2, elem); context.elem_fe_reinit(); const unsigned int n_qp = xyz.size(); for (unsigned int qp=0; qp != n_qp; ++qp) { const Number exact_val = slitfunc(context, xyz[qp]); const Number discrete_val = context.interior_value(0, qp); CPPUNIT_ASSERT_DOUBLES_EQUAL(libmesh_real(exact_val), libmesh_real(discrete_val), TOLERANCE*TOLERANCE); } } }
void testSystem() { SlitFunc slitfunc; unsigned int dim = 2; CPPUNIT_ASSERT_EQUAL( _sys->n_vars(), 1u ); FEMContext context(*_sys); FEBase * fe = NULL; context.get_element_fe( 0, fe, dim ); const std::vector<Point> & xyz = fe->get_xyz(); fe->get_phi(); MeshBase::const_element_iterator el = _mesh->active_local_elements_begin(); const MeshBase::const_element_iterator end_el = _mesh->active_local_elements_end(); for (; el != end_el; ++el) { const Elem * elem = *el; context.pre_fe_reinit(*_sys, elem); context.elem_fe_reinit(); const unsigned int n_qp = xyz.size(); for (unsigned int qp=0; qp != n_qp; ++qp) { const Number exact_val = slitfunc(context, xyz[qp]); const Number discrete_val = context.interior_value(0, qp); CPPUNIT_ASSERT_DOUBLES_EQUAL(libmesh_real(exact_val), libmesh_real(discrete_val), TOLERANCE*TOLERANCE); } } }
void HeatSystem::init_context(DiffContext & context) { FEMContext & c = libmesh_cast_ref<FEMContext &>(context); const std::set<unsigned char> & elem_dims = c.elem_dimensions(); for (std::set<unsigned char>::const_iterator dim_it = elem_dims.begin(); dim_it != elem_dims.end(); ++dim_it) { const unsigned char dim = *dim_it; FEBase * fe = libmesh_nullptr; c.get_element_fe(T_var, fe, dim); fe->get_JxW(); // For integration fe->get_dphi(); // For bilinear form fe->get_xyz(); // For forcing fe->get_phi(); // For forcing } FEMSystem::init_context(context); }
bool HeatSystem::element_time_derivative (bool request_jacobian, DiffContext & context) { FEMContext & c = libmesh_cast_ref<FEMContext &>(context); const unsigned int mesh_dim = c.get_system().get_mesh().mesh_dimension(); // First we get some references to cell-specific data that // will be used to assemble the linear system. const unsigned int dim = c.get_elem().dim(); FEBase * fe = libmesh_nullptr; c.get_element_fe(T_var, fe, dim); // Element Jacobian * quadrature weights for interior integration const std::vector<Real> & JxW = fe->get_JxW(); const std::vector<Point> & xyz = fe->get_xyz(); const std::vector<std::vector<Real> > & phi = fe->get_phi(); const std::vector<std::vector<RealGradient> > & dphi = fe->get_dphi(); // The number of local degrees of freedom in each variable const unsigned int n_T_dofs = c.get_dof_indices(T_var).size(); // The subvectors and submatrices we need to fill: DenseSubMatrix<Number> & K = c.get_elem_jacobian(T_var, T_var); DenseSubVector<Number> & F = c.get_elem_residual(T_var); // Now we will build the element Jacobian and residual. // Constructing the residual requires the solution and its // gradient from the previous timestep. This must be // calculated at each quadrature point by summing the // solution degree-of-freedom values by the appropriate // weight functions. unsigned int n_qpoints = c.get_element_qrule().n_points(); for (unsigned int qp=0; qp != n_qpoints; qp++) { // Compute the solution gradient at the Newton iterate Gradient grad_T = c.interior_gradient(T_var, qp); const Number k = _k[dim]; const Point & p = xyz[qp]; // solution + laplacian depend on problem dimension const Number u_exact = (mesh_dim == 2) ? std::sin(libMesh::pi*p(0)) * std::sin(libMesh::pi*p(1)) : std::sin(libMesh::pi*p(0)) * std::sin(libMesh::pi*p(1)) * std::sin(libMesh::pi*p(2)); // Only apply forcing to interior elements const Number forcing = (dim == mesh_dim) ? -k * u_exact * (dim * libMesh::pi * libMesh::pi) : 0; const Number JxWxNK = JxW[qp] * -k; for (unsigned int i=0; i != n_T_dofs; i++) F(i) += JxWxNK * (grad_T * dphi[i][qp] + forcing * phi[i][qp]); if (request_jacobian) { const Number JxWxNKxD = JxWxNK * context.get_elem_solution_derivative(); for (unsigned int i=0; i != n_T_dofs; i++) for (unsigned int j=0; j != n_T_dofs; ++j) K(i,j) += JxWxNKxD * (dphi[i][qp] * dphi[j][qp]); } } // end of the quadrature point qp-loop return request_jacobian; }
bool SolidSystem::side_time_derivative(bool request_jacobian, DiffContext &context) { FEMContext &c = libmesh_cast_ref<FEMContext&>(context); // Apply displacement boundary conditions with penalty method // Get the current load step Real ratio = this->get_equation_systems().parameters.get<Real>("progress") + 0.001; // The BC are stored in the simulation parameters as array containing sequences of // four numbers: Id of the side for the displacements and three values describing the // displacement. E.g.: bc/displacement = '5 nan nan -1.0'. This will move all nodes of // side 5 about 1.0 units down the z-axis while leaving all other directions unrestricted // Get number of BCs to enforce unsigned int num_bc = args.vector_variable_size("bc/displacement"); if (num_bc % 4 != 0) { libMesh::err << "ERROR, Odd number of values in displacement boundary condition.\n" << std::endl; libmesh_error(); } num_bc /= 4; // Loop over all BCs for (unsigned int nbc = 0; nbc < num_bc; nbc++) { // Get IDs of the side for this BC short int positive_boundary_id = args("bc/displacement", 1, nbc * 4); // The current side may not be on the boundary to be restricted if (!this->get_mesh().boundary_info->has_boundary_id (c.elem,c.side,positive_boundary_id)) continue; // Read values from configuration file Point diff_value; for (unsigned int d = 0; d < c.dim; ++d) { diff_value(d) = args("bc/displacement", NAN, nbc * 4 + 1 + d); } // Scale according to current load step diff_value *= ratio; Real penalty_number = args("bc/displacement_penalty", 1e7); FEBase * fe = c.side_fe_var[var[0]]; const std::vector<std::vector<Real> > & phi = fe->get_phi(); const std::vector<Real>& JxW = fe->get_JxW(); const std::vector<Point>& coords = fe->get_xyz(); unsigned int n_x_dofs = c.dof_indices_var[this->var[0]].size(); // get mappings for dofs for auxiliary system for original mesh positions const System & auxsys = this->get_equation_systems().get_system( "auxiliary"); const DofMap & auxmap = auxsys.get_dof_map(); std::vector<dof_id_type> undefo_dofs[3]; for (unsigned int d = 0; d < c.dim; ++d) { auxmap.dof_indices(c.elem, undefo_dofs[d], undefo_var[d]); } for (unsigned int qp = 0; qp < c.side_qrule->n_points(); ++qp) { // calculate coordinates of qp on undeformed mesh Point orig_point; for (unsigned int i = 0; i < n_x_dofs; ++i) { for (unsigned int d = 0; d < c.dim; ++d) { Number orig_val = auxsys.current_solution(undefo_dofs[d][i]); #if LIBMESH_USE_COMPLEX_NUMBERS orig_point(d) += phi[i][qp] * orig_val.real(); #else orig_point(d) += phi[i][qp] * orig_val; #endif } } // Calculate displacement to be enforced. Point diff = coords[qp] - orig_point - diff_value; // Assemble for (unsigned int i = 0; i < n_x_dofs; ++i) { for (unsigned int d1 = 0; d1 < c.dim; ++d1) { if (libmesh_isnan(diff(d1))) continue; Real val = JxW[qp] * phi[i][qp] * diff(d1) * penalty_number; c.elem_subresiduals[var[d1]]->operator ()(i) += val; } if (request_jacobian) { for (unsigned int j = 0; j < n_x_dofs; ++j) { for (unsigned int d1 = 0; d1 < c.dim; ++d1) { if (libmesh_isnan(diff(d1))) continue; Real val = JxW[qp] * phi[i][qp] * phi[j][qp] * penalty_number; c.elem_subjacobians[var[d1]][var[d1]]->operator ()(i, j) += val; } } } } } } return request_jacobian; }
void testRestart() { SlitFunc slitfunc; _mesh->write("slit_mesh.xda"); _es->write("slit_solution.xda", EquationSystems::WRITE_DATA | EquationSystems::WRITE_SERIAL_FILES); Mesh mesh2(*TestCommWorld); mesh2.read("slit_mesh.xda"); EquationSystems es2(mesh2); es2.read("slit_solution.xda"); System & sys2 = es2.get_system<System> ("SimpleSystem"); unsigned int dim = 2; CPPUNIT_ASSERT_EQUAL( sys2.n_vars(), 1u ); FEMContext context(sys2); FEBase * fe = NULL; context.get_element_fe( 0, fe, dim ); const std::vector<Point> & xyz = fe->get_xyz(); fe->get_phi(); // While we're in the middle of a unique id based test case, let's // make sure our unique ids were all read in correctly too. UniquePtr<PointLocatorBase> locator = _mesh->sub_point_locator(); MeshBase::const_element_iterator el = mesh2.active_local_elements_begin(); const MeshBase::const_element_iterator end_el = mesh2.active_local_elements_end(); for (; el != end_el; ++el) { const Elem * elem = *el; const Elem * mesh1_elem = (*locator)(elem->centroid()); if (mesh1_elem) { CPPUNIT_ASSERT_EQUAL( elem->unique_id(), mesh1_elem->unique_id() ); for (unsigned int n=0; n != elem->n_nodes(); ++n) { const Node & node = elem->node_ref(n); const Node & mesh1_node = mesh1_elem->node_ref(n); CPPUNIT_ASSERT_EQUAL( node.unique_id(), mesh1_node.unique_id() ); } } context.pre_fe_reinit(sys2, elem); context.elem_fe_reinit(); const unsigned int n_qp = xyz.size(); for (unsigned int qp=0; qp != n_qp; ++qp) { const Number exact_val = slitfunc(context, xyz[qp]); const Number discrete_val = context.interior_value(0, qp); CPPUNIT_ASSERT_DOUBLES_EQUAL(libmesh_real(exact_val), libmesh_real(discrete_val), TOLERANCE*TOLERANCE); } } }