void ParsedInteriorQoI::element_qoi_derivative( AssemblyContext& context, const unsigned int qoi_index ) { libMesh::FEBase* element_fe; context.get_element_fe<libMesh::Real>(0, element_fe); const std::vector<libMesh::Real> &JxW = element_fe->get_JxW(); const std::vector<libMesh::Point>& x_qp = element_fe->get_xyz(); // Local DOF count and quadrature point count const unsigned int n_u_dofs = context.get_dof_indices().size(); unsigned int n_qpoints = context.get_element_qrule().n_points(); // Local solution vector - non-const version for finite // differenting purposes libMesh::DenseVector<libMesh::Number>& elem_solution = const_cast<libMesh::DenseVector<libMesh::Number>&> (context.get_elem_solution()); /*! \todo Need to generalize this to the multiple QoI case */ libMesh::DenseVector<libMesh::Number> &Qu = context.get_qoi_derivatives()[qoi_index]; for( unsigned int qp = 0; qp != n_qpoints; qp++ ) { // Central finite differencing to approximate derivatives. // FIXME - we should hook the FParserAD stuff into // ParsedFEMFunction for( unsigned int i = 0; i != n_u_dofs; ++i ) { libMesh::Number ¤t_solution = elem_solution(i); const libMesh::Number original_solution = current_solution; current_solution = original_solution + libMesh::TOLERANCE; const libMesh::Number plus_val = (*qoi_functional)(context, x_qp[qp], context.get_time()); current_solution = original_solution - libMesh::TOLERANCE; const libMesh::Number minus_val = (*qoi_functional)(context, x_qp[qp], context.get_time()); Qu(i) += (plus_val - minus_val) * (0.5 / libMesh::TOLERANCE) * JxW[qp]; // Don't forget to restore the correct solution... current_solution = original_solution; } } }
void AverageNusseltNumber::side_qoi_derivative( AssemblyContext& context, const unsigned int qoi_index ) { for( std::set<libMesh::boundary_id_type>::const_iterator id = _bc_ids.begin(); id != _bc_ids.end(); id++ ) { if( context.has_side_boundary_id( (*id) ) ) { libMesh::FEBase* T_side_fe; context.get_side_fe<libMesh::Real>(this->_T_var, T_side_fe); const std::vector<libMesh::Real> &JxW = T_side_fe->get_JxW(); const std::vector<libMesh::Point>& normals = T_side_fe->get_normals(); unsigned int n_qpoints = context.get_side_qrule().n_points(); const unsigned int n_T_dofs = context.get_dof_indices(_T_var).size(); const std::vector<std::vector<libMesh::Gradient> >& T_gradphi = T_side_fe->get_dphi(); libMesh::DenseSubVector<libMesh::Number>& dQ_dT = context.get_qoi_derivatives(qoi_index, _T_var); // Loop over quadrature points for (unsigned int qp = 0; qp != n_qpoints; qp++) { // Get the solution value at the quadrature point libMesh::Gradient grad_T = 0.0; context.side_gradient(this->_T_var, qp, grad_T); // Update the elemental increment dR for each qp //qoi += (this->_scaling)*(this->_k)*(grad_T*normals[qp])*JxW[qp]; for( unsigned int i = 0; i != n_T_dofs; i++ ) { dQ_dT(i) += _scaling*_k*T_gradphi[i][qp]*normals[qp]*JxW[qp]; } } // quadrature loop } // end check on boundary id } return; }