--- /dev/null
+//---------------------------- dof_constraints_01y.cc ---------------------------
+// $Id$
+// Version: $Name$
+//
+// Copyright (C) 2004 by the deal.II authors
+//
+// This file is subject to QPL and may not be distributed
+// without copyright and license information. Please refer
+// to the file deal.II/doc/license.html for the text and
+// further information on this license.
+//
+//---------------------------- dof_constraints_01y.cc ---------------------------
+
+
+// check DoFConstraints::distribute_local_to_global for matrices and
+// vectors in the presence of both constraints and boundary
+// values. this proved to be a really tricky can of worms. this test
+// checks things on a rather small domain, the sister test
+// dof_constraints_01y does it on complicated meshes
+
+#include "../tests.h"
+#include <base/function_lib.h>
+#include <lac/sparsity_pattern.h>
+#include <lac/sparse_matrix.h>
+#include <lac/vector.h>
+#include <grid/tria.h>
+#include <grid/tria_accessor.h>
+#include <grid/tria_iterator.h>
+#include <grid/grid_tools.h>
+#include <grid/grid_generator.h>
+#include <dofs/dof_handler.h>
+#include <dofs/dof_accessor.h>
+#include <dofs/dof_tools.h>
+#include <dofs/dof_constraints.h>
+#include <numerics/vectors.h>
+#include <numerics/matrices.h>
+#include <fe/fe_q.h>
+#include <fstream>
+#include <iostream>
+
+
+template <int dim>
+void test ()
+{
+ deallog << dim << "D" << std::endl;
+
+ Triangulation<dim> triangulation;
+ GridGenerator::hyper_cube (triangulation);
+
+ // set boundary conditions on part of the boundary
+ for (unsigned int i=0; i<dim; ++i)
+ triangulation.begin_active()->face(i)->set_boundary_indicator (1);
+
+ // refine the mesh in a random way so as to
+ // generate as many hanging node
+ // constraints as possible
+ triangulation.refine_global (4-dim);
+ for (unsigned int i=0; i<11-2*dim; ++i)
+ {
+ typename Triangulation<dim>::active_cell_iterator
+ cell = triangulation.begin_active();
+ for (unsigned int index=0; cell != triangulation.end(); ++cell, ++index)
+ if (index % (3*dim) == 0)
+ cell->set_refine_flag();
+ triangulation.execute_coarsening_and_refinement ();
+ }
+
+ deallog << "Number of cells: " << triangulation.n_active_cells() << std::endl;
+
+ // set up a DoFHandler and compute hanging
+ // node constraints
+ FE_Q<dim> fe(1);
+ DoFHandler<dim> dof_handler (triangulation);
+ dof_handler.distribute_dofs (fe);
+ deallog << "Number of dofs: " << dof_handler.n_dofs() << std::endl;
+
+ ConstraintMatrix constraints;
+ DoFTools::make_hanging_node_constraints (dof_handler, constraints);
+ constraints.close ();
+ deallog << "Number of constraints: " << constraints.n_constraints() << std::endl;
+
+ // compute some boundary values
+ std::map<unsigned int,double> boundary_values;
+ VectorTools::interpolate_boundary_values (dof_handler, 0,
+ ConstantFunction<dim> (1.),
+ boundary_values);
+
+ // then set up a sparsity pattern and two
+ // matrices on top of it
+ SparsityPattern sparsity (dof_handler.n_dofs(),
+ dof_handler.n_dofs(),
+ dof_handler.max_couplings_between_dofs());
+ DoFTools::make_sparsity_pattern (dof_handler, sparsity);
+ constraints.condense (sparsity);
+ SparseMatrix<double> A(sparsity), B(sparsity);
+ Vector<double> a(dof_handler.n_dofs()), b(dof_handler.n_dofs());
+
+ // then fill the two matrices by setting up
+ // bogus matrix entries and (1) writing
+ // them into the matrix and condensing away
+ // hanging node constraints later on, or
+ // (2) distributing them right away
+ std::vector<unsigned int> local_dofs (fe.dofs_per_cell);
+ FullMatrix<double> local_matrix (fe.dofs_per_cell, fe.dofs_per_cell);
+ Vector<double> local_vector (fe.dofs_per_cell);
+
+ for (typename DoFHandler<dim>::active_cell_iterator
+ cell = dof_handler.begin_active();
+ cell != dof_handler.end(); ++cell)
+ {
+ cell->get_dof_indices (local_dofs);
+ local_matrix = 0;
+ local_vector = 0;
+ for (unsigned int i=0; i<fe.dofs_per_cell; ++i)
+ for (unsigned int j=0; j<fe.dofs_per_cell; ++j)
+ local_matrix(i,j) = 1;
+
+ for (unsigned int i=0; i<fe.dofs_per_cell; ++i)
+ local_vector(i) = i;
+
+ // copy local to global by ourselves
+ for (unsigned int i=0; i<fe.dofs_per_cell; ++i)
+ for (unsigned int j=0; j<fe.dofs_per_cell; ++j)
+ A.add (local_dofs[i], local_dofs[j], local_matrix(i,j));
+ for (unsigned int i=0; i<fe.dofs_per_cell; ++i)
+ a(local_dofs[i]) += local_vector(i);
+
+ // or let other functions do that
+ MatrixTools::local_apply_boundary_values (boundary_values,
+ local_dofs,
+ local_matrix,
+ local_vector,
+ true);
+ constraints.distribute_local_to_global (local_matrix, local_dofs,
+ boundary_values, B);
+ constraints.distribute_local_to_global (local_vector, local_dofs,
+ boundary_values, b);
+ }
+
+ // now condense away constraints from A
+ constraints.condense (A);
+ Vector<double> x (dof_handler.n_dofs());
+ MatrixTools::apply_boundary_values (boundary_values, A, x, a);
+
+ // we haven't yet set the diagonal entries
+ // for constrained nodes. we can do so at
+ // will, since these values don't matter
+ // anyway
+ for (unsigned int i=0; i<dof_handler.n_dofs(); ++i)
+ if (constraints.is_constrained(i))
+ B.set(i,i,A(i,i));
+
+ // the diagonal elements of
+ // boundary nodes are computed in
+ // different ways, so make sure
+ // that the boundary values will be
+ // correct
+ for (unsigned int i=0; i<dof_handler.n_dofs(); ++i)
+ if (boundary_values.find(i) != boundary_values.end())
+ {
+ B.diag_element(i) = A.diag_element(i);
+ b(i) = a(i);
+ }
+
+ // output constraints and boundary values
+ deallog << "CONSTRAINTS:" << std::endl;
+ constraints.print (deallog.get_file_stream());
+
+ deallog << "BOUNDARY VALUES:" << std::endl;
+ for (unsigned int i=0; i<dof_handler.n_dofs(); ++i)
+ if (boundary_values.find(i) != boundary_values.end())
+ deallog << i << ' ' << boundary_values[i]
+ << std::endl;
+
+ // output both matrices. at the
+ // time of writing this test, the
+ // matrices were different and we
+ // needed to figure out what was
+ // going on. since the matrices
+ // aren't big, we just leave the
+ // output here:
+ deallog << "MATRIX A:" << std::endl;
+ A.print (deallog.get_file_stream());
+
+ deallog << "MATRIX B:" << std::endl;
+ B.print (deallog.get_file_stream());
+
+ // now comes the check: we subtract B from
+ // A, and make sure that the result is zero
+ A.add_scaled (-1., B);
+
+ deallog << "MATRIX DIFFERENCE:" << std::endl;
+ A.print (deallog.get_file_stream());
+
+ deallog << "RHS VECTORS:" << std::endl;
+ for (unsigned int i=0; i<dof_handler.n_dofs(); ++i)
+ deallog << a(i) << ' ' << b(i)
+ << (boundary_values.find(i) != boundary_values.end() ? " b" : " ")
+ << (constraints.is_constrained(i) ? " c" : "")
+ << std::endl;
+
+ deallog << "|A|=" << A.frobenius_norm() << std::endl;
+ deallog << "|B|=" << B.frobenius_norm() << std::endl;
+ Assert (A.frobenius_norm() < 1e-12*B.frobenius_norm(),
+ ExcInternalError());
+}
+
+
+
+int main ()
+{
+ std::ofstream logfile("dof_constraints_01y.output");
+ deallog.attach(logfile);
+ deallog.depth_console(0);
+
+ try
+ {
+ test<2> ();
+ test<3> ();
+ }
+ catch (std::exception &exc)
+ {
+ std::cerr << std::endl << std::endl
+ << "----------------------------------------------------"
+ << std::endl;
+ std::cerr << "Exception on processing: " << std::endl
+ << exc.what() << std::endl
+ << "Aborting!" << std::endl
+ << "----------------------------------------------------"
+ << std::endl;
+
+ return 1;
+ }
+ catch (...)
+ {
+ std::cerr << std::endl << std::endl
+ << "----------------------------------------------------"
+ << std::endl;
+ std::cerr << "Unknown exception!" << std::endl
+ << "Aborting!" << std::endl
+ << "----------------------------------------------------"
+ << std::endl;
+ return 1;
+ };
+}