--- /dev/null
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2018 - 2020 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, redistribute
+// it, and/or modify it under the terms of the GNU Lesser General
+// Public License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE.md at
+// the top level directory of deal.II.
+//
+// ---------------------------------------------------------------------
+
+
+
+// tests matrix-free face evaluation when only boundary faces but not inner
+// faces are enabled. Otherwise the same test as matrix_vector_faces_05 (FE_Q,
+// Laplacian, weak imposition of Dirichlet boundary condition)
+
+#include <deal.II/base/function.h>
+
+#include <deal.II/fe/fe_q.h>
+
+#include "../tests.h"
+
+#include "matrix_vector_faces_common.h"
+
+template <int dim, int fe_degree>
+void
+test()
+{
+ Triangulation<dim> tria;
+ GridGenerator::hyper_cube(tria);
+ tria.refine_global(5 - dim);
+
+ FE_Q<dim> fe(fe_degree);
+ DoFHandler<dim> dof(tria);
+ dof.distribute_dofs(fe);
+ AffineConstraints<double> constraints;
+ constraints.close();
+
+ deallog << "Testing " << dof.get_fe().get_name();
+ deallog << std::endl;
+ // std::cout << "Number of cells: " <<
+ // dof.get_triangulation().n_active_cells() << std::endl; std::cout << "Number
+ // of degrees of freedom: " << dof.n_dofs() << std::endl; std::cout << "Number
+ // of constraints: " << constraints.n_constraints() << std::endl;
+
+ MappingQ<dim> mapping(dof.get_fe().degree + 1);
+
+ Vector<double> in(dof.n_dofs()), out(dof.n_dofs());
+ Vector<double> out_dist(out);
+
+ // Set random seed for reproducibility
+ Testing::srand(42);
+ for (unsigned int i = 0; i < dof.n_dofs(); ++i)
+ {
+ if (constraints.is_constrained(i))
+ continue;
+ const double entry = Testing::rand() / (double)RAND_MAX;
+ in(i) = entry;
+ }
+
+ constexpr unsigned int n_q_points_1d = fe_degree + 1;
+
+ // assemble sparse matrix with MeshWorker
+ SparsityPattern sparsity;
+ SparseMatrix<double> matrix;
+ {
+ DynamicSparsityPattern d_sparsity(dof.n_dofs());
+ DoFTools::make_flux_sparsity_pattern(dof, d_sparsity);
+ sparsity.copy_from(d_sparsity);
+ }
+ matrix.reinit(sparsity);
+ MeshWorker::IntegrationInfoBox<dim> info_box;
+ UpdateFlags update_flags =
+ update_values | update_gradients | update_jacobians;
+ info_box.add_update_flags_all(update_flags);
+ info_box.initialize_gauss_quadrature(n_q_points_1d,
+ n_q_points_1d,
+ n_q_points_1d);
+ info_box.initialize(dof.get_fe(), mapping);
+
+ MeshWorker::DoFInfo<dim> dof_info(dof);
+
+ MeshWorker::Assembler::MatrixSimple<SparseMatrix<double>> assembler;
+ assembler.initialize(matrix);
+
+ MatrixIntegrator<dim> integrator;
+ MeshWorker::integration_loop<dim, dim>(
+ dof.begin_active(), dof.end(), dof_info, info_box, integrator, assembler);
+
+ matrix.vmult(out, in);
+
+ // zero constrained dofs
+ for (unsigned int i = 0; i < dof.n_dofs(); ++i)
+ if (constraints.is_constrained(i))
+ out(i) = 0;
+
+ MatrixFree<dim, double> mf_data;
+ const QGauss<1> quad(n_q_points_1d > 0 ? n_q_points_1d :
+ dof.get_fe().degree + 1);
+ typename MatrixFree<dim, double>::AdditionalData data;
+ data.tasks_parallel_scheme = MatrixFree<dim, double>::AdditionalData::none;
+ data.tasks_block_size = 3;
+ data.mapping_update_flags_boundary_faces =
+ (update_gradients | update_JxW_values);
+
+ mf_data.reinit(mapping, dof, constraints, quad, data);
+
+ // Check that only boundary faces are set up as requested
+ Assert(mf_data.n_inner_face_batches() == 0, ExcInternalError());
+ Assert(mf_data.n_boundary_face_batches() > 0, ExcInternalError());
+
+ MatrixFreeTest<dim, fe_degree, n_q_points_1d, double, Vector<double>, 1> mf(
+ mf_data);
+ mf.vmult(out_dist, in);
+
+ out_dist -= out;
+ const double diff_norm = out_dist.linfty_norm() / out.linfty_norm();
+ deallog << "Norm of difference: " << diff_norm << std::endl;
+
+ deallog << std::endl;
+}