]> https://gitweb.dealii.org/ - dealii.git/commitdiff
GMG: add MGCoarseGridPreconditioner to apply a few steps of smoother at the coarse...
authorDenis Davydov <davydden@gmail.com>
Tue, 9 Aug 2016 14:08:43 +0000 (16:08 +0200)
committerDenis Davydov <davydden@gmail.com>
Tue, 9 Aug 2016 15:37:00 +0000 (17:37 +0200)
include/deal.II/multigrid/mg_coarse.h
tests/multigrid/step-16-50-mpi-smoother.cc [new file with mode: 0644]
tests/multigrid/step-16-50-mpi-smoother.with_mpi=true.with_trilinos=true.with_p4est=true.mpirun=3.output [new file with mode: 0644]

index db6b57a2bdb36a9021f777c4e4125323a3fc85fa..b4cff26a1cf6a2f180d2e5446b7eda059aa1635c 100644 (file)
@@ -27,6 +27,47 @@ DEAL_II_NAMESPACE_OPEN
 /*!@addtogroup mg */
 /*@{*/
 
+/**
+ * Coarse grid solver using preconditioners only. This is a little wrapper,
+ * transforming a preconditioner into
+ * a coarse grid solver.
+ *
+ * @author Denis Davydov, 2016.
+ */
+template<class VectorType = Vector<double> >
+class MGCoarseGridApplySmoother :  public MGCoarseGridBase<VectorType>
+{
+public:
+  /**
+   * Default constructor.
+   */
+  MGCoarseGridApplySmoother ();
+
+  /**
+   * Constructor. Store preconditioner for later use.
+   */
+  MGCoarseGridApplySmoother (const MGSmootherBase<VectorType> &coarse_smooth);
+
+  /**
+   * Initialize new data.
+   */
+  void initialize (const MGSmootherBase<VectorType> &coarse_smooth);
+
+  /**
+   * Implementation of the abstract function.
+   */
+  void operator() (const unsigned int level,
+                   VectorType         &dst,
+                   const VectorType   &src) const;
+
+private:
+  /**
+   * Reference to the preconditioner.
+   */
+  SmartPointer<const MGSmootherBase<VectorType>,Multigrid<VectorType> > coarse_smooth;
+};
+
+
 /**
  * Coarse grid solver using LAC iterative methods. This is a little wrapper,
  * transforming a triplet of iterative solver, matrix and preconditioner into
@@ -185,6 +226,39 @@ private:
 /*@}*/
 
 #ifndef DOXYGEN
+/* ------------------ Functions for MGCoarseGridApplySmoother -----------*/
+template<class VectorType>
+MGCoarseGridApplySmoother<VectorType>::MGCoarseGridApplySmoother ()
+  : coarse_smooth(NULL)
+{
+}
+
+template<class VectorType>
+MGCoarseGridApplySmoother<VectorType>::MGCoarseGridApplySmoother (const MGSmootherBase<VectorType> &coarse_smooth)
+  : coarse_smooth(NULL)
+{
+  initialize(coarse_smooth);
+}
+
+
+template<class VectorType>
+void
+MGCoarseGridApplySmoother<VectorType>::initialize (const MGSmootherBase<VectorType> &coarse_smooth_)
+{
+  coarse_smooth =
+    SmartPointer<const MGSmootherBase<VectorType>,Multigrid<VectorType> >
+    (&coarse_smooth_,typeid(*this).name());
+}
+
+template<class VectorType>
+void
+MGCoarseGridApplySmoother<VectorType>::operator() (const unsigned int level,
+                                                   VectorType         &dst,
+                                                   const VectorType   &src) const
+{
+  coarse_smooth->smooth(level, dst, src);
+}
+
 /* ------------------ Functions for MGCoarseGridLACIteration ------------ */
 
 
diff --git a/tests/multigrid/step-16-50-mpi-smoother.cc b/tests/multigrid/step-16-50-mpi-smoother.cc
new file mode 100644 (file)
index 0000000..71544b6
--- /dev/null
@@ -0,0 +1,581 @@
+/* ---------------------------------------------------------------------
+ *
+ * Copyright (C) 2016 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 at
+ * the top level of the deal.II distribution.
+ *
+ * ---------------------------------------------------------------------
+ */
+
+// Same as step-16-50, but use Jacobi smoother at the coarsest grid via MGCoarseGridApplySmoother.
+// In this particular case, the number of iterations untill convergence is
+// exactly the same as for MGCoarseGridLACIteration.
+
+#include "../tests.h"
+
+#include <deal.II/base/quadrature_lib.h>
+#include <deal.II/base/function.h>
+#include <deal.II/base/logstream.h>
+#include <deal.II/base/utilities.h>
+#include <deal.II/base/conditional_ostream.h>
+
+#include <deal.II/lac/constraint_matrix.h>
+#include <deal.II/lac/vector.h>
+#include <deal.II/lac/full_matrix.h>
+#include <deal.II/lac/sparse_matrix.h>
+#include <deal.II/lac/solver_cg.h>
+#include <deal.II/lac/solver_gmres.h>
+#include <deal.II/lac/precondition.h>
+
+#include <deal.II/grid/tria.h>
+#include <deal.II/grid/tria_accessor.h>
+#include <deal.II/grid/tria_iterator.h>
+#include <deal.II/grid/grid_generator.h>
+#include <deal.II/grid/grid_out.h>
+#include <deal.II/grid/grid_refinement.h>
+#include <deal.II/grid/tria_boundary_lib.h>
+
+#include <deal.II/dofs/dof_accessor.h>
+#include <deal.II/dofs/dof_tools.h>
+
+#include <deal.II/fe/fe_q.h>
+#include <deal.II/fe/fe_values.h>
+
+#include <deal.II/numerics/vector_tools.h>
+#include <deal.II/numerics/data_out.h>
+#include <deal.II/numerics/error_estimator.h>
+
+#include <deal.II/base/index_set.h>
+#include <deal.II/distributed/tria.h>
+#include <deal.II/distributed/grid_refinement.h>
+
+#include <deal.II/multigrid/mg_constrained_dofs.h>
+#include <deal.II/multigrid/multigrid.h>
+#include <deal.II/multigrid/mg_transfer.h>
+#include <deal.II/multigrid/mg_tools.h>
+#include <deal.II/multigrid/mg_coarse.h>
+#include <deal.II/multigrid/mg_smoother.h>
+#include <deal.II/multigrid/mg_matrix.h>
+
+
+#include <deal.II/lac/generic_linear_algebra.h>
+
+
+namespace LA
+{
+#ifdef USE_PETSC_LA
+  using namespace dealii::LinearAlgebraPETSc;
+#else
+  using namespace dealii::LinearAlgebraTrilinos;
+#endif
+}
+
+#include <iostream>
+#include <fstream>
+#include <sstream>
+
+namespace Step50
+{
+  using namespace dealii;
+
+
+
+  template <int dim>
+  class LaplaceProblem
+  {
+  public:
+    LaplaceProblem (const unsigned int deg);
+    void run ();
+
+  private:
+    void setup_system ();
+    void assemble_system ();
+    void assemble_multigrid ();
+    void solve ();
+    void refine_grid ();
+
+    parallel::distributed::Triangulation<dim>   triangulation;
+    FE_Q<dim>            fe;
+    DoFHandler<dim>    mg_dof_handler;
+
+    typedef LA::MPI::SparseMatrix matrix_t;
+    typedef LA::MPI::Vector vector_t;
+
+    matrix_t system_matrix;
+
+    IndexSet locally_relevant_set;
+
+    ConstraintMatrix     hanging_node_constraints;
+    ConstraintMatrix     constraints;
+
+    vector_t       solution;
+    vector_t       system_rhs;
+
+    const unsigned int degree;
+
+    MGLevelObject<matrix_t> mg_matrices;
+    MGLevelObject<matrix_t> mg_interface_matrices;
+    MGConstrainedDoFs                    mg_constrained_dofs;
+  };
+
+
+
+
+
+  template <int dim>
+  class Coefficient : public Function<dim>
+  {
+  public:
+    Coefficient () : Function<dim>() {}
+
+    virtual double value (const Point<dim>   &p,
+                          const unsigned int  component = 0) const;
+
+    virtual void value_list (const std::vector<Point<dim> > &points,
+                             std::vector<double>            &values,
+                             const unsigned int              component = 0) const;
+  };
+
+
+
+  template <int dim>
+  double Coefficient<dim>::value (const Point<dim> &p,
+                                  const unsigned int) const
+  {
+    if (p.square() < 0.5*0.5)
+      return 5;
+    else
+      return 1;
+  }
+
+
+
+  template <int dim>
+  void Coefficient<dim>::value_list (const std::vector<Point<dim> > &points,
+                                     std::vector<double>            &values,
+                                     const unsigned int              component) const
+  {
+    const unsigned int n_points = points.size();
+
+    Assert (values.size() == n_points,
+            ExcDimensionMismatch (values.size(), n_points));
+
+    Assert (component == 0,
+            ExcIndexRange (component, 0, 1));
+
+    for (unsigned int i=0; i<n_points; ++i)
+      values[i] = Coefficient<dim>::value (points[i]);
+  }
+
+
+
+
+  template <int dim>
+  LaplaceProblem<dim>::LaplaceProblem (const unsigned int degree)
+    :
+    triangulation (MPI_COMM_WORLD,Triangulation<dim>::
+                   limit_level_difference_at_vertices,
+                   parallel::distributed::Triangulation<dim>::construct_multigrid_hierarchy),
+    fe (degree),
+    mg_dof_handler (triangulation),
+    degree(degree)
+  {}
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::setup_system ()
+  {
+    mg_dof_handler.distribute_dofs (fe);
+    mg_dof_handler.distribute_mg_dofs (fe);
+
+    DoFTools::extract_locally_relevant_dofs (mg_dof_handler,
+                                             locally_relevant_set);
+
+    solution.reinit(mg_dof_handler.locally_owned_dofs(), MPI_COMM_WORLD);
+    system_rhs.reinit(mg_dof_handler.locally_owned_dofs(), MPI_COMM_WORLD);
+
+    constraints.reinit (locally_relevant_set);
+    hanging_node_constraints.reinit (locally_relevant_set);
+    DoFTools::make_hanging_node_constraints (mg_dof_handler, hanging_node_constraints);
+    DoFTools::make_hanging_node_constraints (mg_dof_handler, constraints);
+
+    typename FunctionMap<dim>::type      dirichlet_boundary;
+    ZeroFunction<dim>                    homogeneous_dirichlet_bc;
+    dirichlet_boundary[0] = &homogeneous_dirichlet_bc;
+    VectorTools::interpolate_boundary_values (mg_dof_handler,
+                                              dirichlet_boundary,
+                                              constraints);
+    constraints.close ();
+    hanging_node_constraints.close ();
+
+    DynamicSparsityPattern dsp(mg_dof_handler.n_dofs(), mg_dof_handler.n_dofs());
+    DoFTools::make_sparsity_pattern (mg_dof_handler, dsp, constraints);
+    system_matrix.reinit (mg_dof_handler.locally_owned_dofs(), dsp, MPI_COMM_WORLD, true);
+
+
+    mg_constrained_dofs.clear();
+    mg_constrained_dofs.initialize(mg_dof_handler, dirichlet_boundary);
+
+
+    const unsigned int n_levels = triangulation.n_global_levels();
+
+    mg_interface_matrices.resize(0, n_levels-1);
+    mg_interface_matrices.clear_elements ();
+    mg_matrices.resize(0, n_levels-1);
+    mg_matrices.clear_elements ();
+
+    for (unsigned int level=0; level<n_levels; ++level)
+      {
+        DynamicSparsityPattern dsp(mg_dof_handler.n_dofs(level),
+                                   mg_dof_handler.n_dofs(level));
+        MGTools::make_sparsity_pattern(mg_dof_handler, dsp, level);
+
+        mg_matrices[level].reinit(mg_dof_handler.locally_owned_mg_dofs(level),
+                                  mg_dof_handler.locally_owned_mg_dofs(level),
+                                  dsp,
+                                  MPI_COMM_WORLD, true);
+
+        mg_interface_matrices[level].reinit(mg_dof_handler.locally_owned_mg_dofs(level),
+                                            mg_dof_handler.locally_owned_mg_dofs(level),
+                                            dsp,
+                                            MPI_COMM_WORLD, true);
+      }
+  }
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::assemble_system ()
+  {
+    const QGauss<dim>  quadrature_formula(degree+1);
+
+    FEValues<dim> fe_values (fe, quadrature_formula,
+                             update_values    |  update_gradients |
+                             update_quadrature_points  |  update_JxW_values);
+
+    const unsigned int   dofs_per_cell = fe.dofs_per_cell;
+    const unsigned int   n_q_points    = quadrature_formula.size();
+
+    FullMatrix<double>   cell_matrix (dofs_per_cell, dofs_per_cell);
+    Vector<double>       cell_rhs (dofs_per_cell);
+
+    std::vector<types::global_dof_index> local_dof_indices (dofs_per_cell);
+
+    const Coefficient<dim> coefficient;
+    std::vector<double>    coefficient_values (n_q_points);
+
+    typename DoFHandler<dim>::active_cell_iterator
+    cell = mg_dof_handler.begin_active(),
+    endc = mg_dof_handler.end();
+    for (; cell!=endc; ++cell)
+      if (cell->is_locally_owned())
+        {
+          cell_matrix = 0;
+          cell_rhs = 0;
+
+          fe_values.reinit (cell);
+
+          coefficient.value_list (fe_values.get_quadrature_points(),
+                                  coefficient_values);
+
+          for (unsigned int q_point=0; q_point<n_q_points; ++q_point)
+            for (unsigned int i=0; i<dofs_per_cell; ++i)
+              {
+                for (unsigned int j=0; j<dofs_per_cell; ++j)
+                  cell_matrix(i,j) += (coefficient_values[q_point] *
+                                       fe_values.shape_grad(i,q_point) *
+                                       fe_values.shape_grad(j,q_point) *
+                                       fe_values.JxW(q_point));
+
+                cell_rhs(i) += (fe_values.shape_value(i,q_point) *
+                                10.0 *
+                                fe_values.JxW(q_point));
+              }
+
+          cell->get_dof_indices (local_dof_indices);
+          constraints.distribute_local_to_global (cell_matrix, cell_rhs,
+                                                  local_dof_indices,
+                                                  system_matrix, system_rhs);
+        }
+
+    system_matrix.compress(VectorOperation::add);
+    system_rhs.compress(VectorOperation::add);
+  }
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::assemble_multigrid ()
+  {
+    QGauss<dim>  quadrature_formula(1+degree);
+
+    FEValues<dim> fe_values (fe, quadrature_formula,
+                             update_values   | update_gradients |
+                             update_quadrature_points | update_JxW_values);
+
+    const unsigned int   dofs_per_cell   = fe.dofs_per_cell;
+    const unsigned int   n_q_points      = quadrature_formula.size();
+
+    FullMatrix<double>   cell_matrix (dofs_per_cell, dofs_per_cell);
+
+    std::vector<types::global_dof_index> local_dof_indices (dofs_per_cell);
+
+    const Coefficient<dim> coefficient;
+    std::vector<double>    coefficient_values (n_q_points);
+
+
+
+    std::vector<ConstraintMatrix> boundary_constraints (triangulation.n_global_levels());
+    ConstraintMatrix empty_constraints;
+    for (unsigned int level=0; level<triangulation.n_global_levels(); ++level)
+      {
+        IndexSet dofset;
+        DoFTools::extract_locally_relevant_level_dofs (mg_dof_handler, level, dofset);
+        boundary_constraints[level].reinit(dofset);
+        boundary_constraints[level].add_lines (mg_constrained_dofs.get_refinement_edge_indices(level));
+        boundary_constraints[level].add_lines (mg_constrained_dofs.get_boundary_indices(level));
+
+        boundary_constraints[level].close ();
+      }
+
+    typename DoFHandler<dim>::cell_iterator cell = mg_dof_handler.begin(),
+                                            endc = mg_dof_handler.end();
+
+    for (; cell!=endc; ++cell)
+      if (cell->level_subdomain_id()==triangulation.locally_owned_subdomain())
+        {
+          cell_matrix = 0;
+          fe_values.reinit (cell);
+
+          coefficient.value_list (fe_values.get_quadrature_points(),
+                                  coefficient_values);
+
+          for (unsigned int q_point=0; q_point<n_q_points; ++q_point)
+            for (unsigned int i=0; i<dofs_per_cell; ++i)
+              for (unsigned int j=0; j<dofs_per_cell; ++j)
+                cell_matrix(i,j) += (coefficient_values[q_point] *
+                                     fe_values.shape_grad(i,q_point) *
+                                     fe_values.shape_grad(j,q_point) *
+                                     fe_values.JxW(q_point));
+
+          cell->get_mg_dof_indices (local_dof_indices);
+
+          boundary_constraints[cell->level()]
+          .distribute_local_to_global (cell_matrix,
+                                       local_dof_indices,
+                                       mg_matrices[cell->level()]);
+
+
+          const IndexSet &interface_dofs_on_level
+            = mg_constrained_dofs.get_refinement_edge_indices(cell->level());
+          const unsigned int lvl = cell->level();
+
+          for (unsigned int i=0; i<dofs_per_cell; ++i)
+            for (unsigned int j=0; j<dofs_per_cell; ++j)
+              if (interface_dofs_on_level.is_element(local_dof_indices[i])   // at_refinement_edge(i)
+                  &&
+                  !interface_dofs_on_level.is_element(local_dof_indices[j])   // !at_refinement_edge(j)
+                  &&
+                  (
+                    (!mg_constrained_dofs.is_boundary_index(lvl, local_dof_indices[i])
+                     &&
+                     !mg_constrained_dofs.is_boundary_index(lvl, local_dof_indices[j])
+                    ) // ( !boundary(i) && !boundary(j) )
+                    ||
+                    (
+                      mg_constrained_dofs.is_boundary_index(lvl, local_dof_indices[i])
+                      &&
+                      local_dof_indices[i]==local_dof_indices[j]
+                    ) // ( boundary(i) && boundary(j) && i==j )
+                  )
+                 )
+                {
+                }
+              else
+                {
+                  cell_matrix(i,j) = 0;
+                }
+
+
+          empty_constraints
+          .distribute_local_to_global (cell_matrix,
+                                       local_dof_indices,
+                                       mg_interface_matrices[cell->level()]);
+        }
+
+    for (unsigned int i=0; i<triangulation.n_global_levels(); ++i)
+      {
+        mg_matrices[i].compress(VectorOperation::add);
+        mg_interface_matrices[i].compress(VectorOperation::add);
+      }
+  }
+
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::solve ()
+  {
+    MGTransferPrebuilt<vector_t> mg_transfer(hanging_node_constraints, mg_constrained_dofs);
+    mg_transfer.build_matrices(mg_dof_handler);
+
+    // pre and post smoothers:
+    typedef LA::MPI::PreconditionJacobi Smoother;
+    MGSmootherPrecondition<matrix_t, Smoother, vector_t> mg_smoother;
+    mg_smoother.initialize(mg_matrices, Smoother::AdditionalData(0.5));
+    mg_smoother.set_steps(2);
+
+    // coarse grid solver:
+    MGSmootherPrecondition<matrix_t, Smoother, vector_t> mg_coase_grid_smoother;
+    mg_coase_grid_smoother.initialize(mg_matrices, Smoother::AdditionalData(0.5));
+    mg_coase_grid_smoother.set_steps(2);
+    mg_coase_grid_smoother.set_symmetric(true);
+    MGCoarseGridApplySmoother<vector_t> coarse_grid_solver(mg_coase_grid_smoother);
+
+
+    mg::Matrix<vector_t> mg_matrix(mg_matrices);
+    mg::Matrix<vector_t> mg_interface_up(mg_interface_matrices);
+    mg::Matrix<vector_t> mg_interface_down(mg_interface_matrices);
+
+    Multigrid<vector_t > mg(mg_dof_handler,
+                            mg_matrix,
+                            coarse_grid_solver,
+                            mg_transfer,
+                            mg_smoother,
+                            mg_smoother);
+    mg.set_edge_matrices(mg_interface_down, mg_interface_up);
+
+    PreconditionMG<dim, vector_t, MGTransferPrebuilt<vector_t> >
+    preconditioner(mg_dof_handler, mg, mg_transfer);
+
+
+    SolverControl solver_control (500, 1e-8*system_rhs.l2_norm(), false);
+    SolverCG<vector_t> solver (solver_control);
+
+    solution = 0;
+    solver.solve (system_matrix, solution, system_rhs,
+                  preconditioner);
+    constraints.distribute (solution);
+  }
+
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::refine_grid ()
+  {
+    Vector<float> estimated_error_per_cell (triangulation.n_active_cells());
+
+    LA::MPI::Vector temp_solution;
+    temp_solution.reinit(locally_relevant_set, MPI_COMM_WORLD);
+    temp_solution = solution;
+
+    KellyErrorEstimator<dim>::estimate (static_cast<DoFHandler<dim>&>(mg_dof_handler),
+                                        QGauss<dim-1>(degree+1),
+                                        typename FunctionMap<dim>::type(),
+                                        temp_solution,
+                                        estimated_error_per_cell);
+
+    const double threshold = 0.6 * Utilities::MPI::max(estimated_error_per_cell.linfty_norm(),MPI_COMM_WORLD);
+    GridRefinement::refine (triangulation, estimated_error_per_cell, threshold);
+
+    for (typename Triangulation<dim>::active_cell_iterator
+         cell = triangulation.begin_active();
+         cell != triangulation.end(); ++cell)
+      if (cell->subdomain_id() != triangulation.locally_owned_subdomain())
+        {
+          cell->clear_refine_flag ();
+          cell->clear_coarsen_flag ();
+        }
+
+    triangulation.execute_coarsening_and_refinement ();
+  }
+
+  template <int dim>
+  void LaplaceProblem<dim>::run ()
+  {
+    for (unsigned int cycle=0; cycle<5; ++cycle)
+      {
+        deallog << "Cycle " << cycle << ':' << std::endl;
+
+        if (cycle == 0)
+          {
+            GridGenerator::hyper_cube (triangulation);
+
+            triangulation.refine_global (4);
+          }
+        else
+          refine_grid ();
+
+        deallog << "   Number of active cells:       "
+                << triangulation.n_global_active_cells()
+                << std::endl;
+
+        setup_system ();
+
+        deallog << "   Number of degrees of freedom: "
+                << mg_dof_handler.n_dofs()
+                << " (by level: ";
+        for (unsigned int level=0; level<triangulation.n_global_levels(); ++level)
+          deallog << mg_dof_handler.n_dofs(level)
+                  << (level == triangulation.n_global_levels()-1
+                      ? ")" : ", ");
+        deallog << std::endl;
+
+        assemble_system ();
+        assemble_multigrid ();
+
+        solve ();
+      }
+  }
+}
+
+
+int main (int argc, char *argv[])
+{
+  dealii::Utilities::MPI::MPI_InitFinalize mpi_initialization(argc, argv, 1);
+
+  mpi_initlog();
+
+  try
+    {
+      using namespace dealii;
+      using namespace Step50;
+
+      LaplaceProblem<2> laplace_problem(1/*degree*/);
+      laplace_problem.run ();
+    }
+  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;
+      throw;
+    }
+  catch (...)
+    {
+      std::cerr << std::endl << std::endl
+                << "----------------------------------------------------"
+                << std::endl;
+      std::cerr << "Unknown exception!" << std::endl
+                << "Aborting!" << std::endl
+                << "----------------------------------------------------"
+                << std::endl;
+      throw;
+    }
+
+  return 0;
+}
diff --git a/tests/multigrid/step-16-50-mpi-smoother.with_mpi=true.with_trilinos=true.with_p4est=true.mpirun=3.output b/tests/multigrid/step-16-50-mpi-smoother.with_mpi=true.with_trilinos=true.with_p4est=true.mpirun=3.output
new file mode 100644 (file)
index 0000000..3f3684c
--- /dev/null
@@ -0,0 +1,26 @@
+
+DEAL::Cycle 0:
+DEAL::   Number of active cells:       256
+DEAL::   Number of degrees of freedom: 289 (by level: 4, 9, 25, 81, 289)
+DEAL:cg::Starting value 0.585938
+DEAL:cg::Convergence step 7 value 4.58200e-09
+DEAL::Cycle 1:
+DEAL::   Number of active cells:       418
+DEAL::   Number of degrees of freedom: 495 (by level: 4, 9, 25, 81, 289, 305)
+DEAL:cg::Starting value 0.533937
+DEAL:cg::Convergence step 10 value 7.40543e-10
+DEAL::Cycle 2:
+DEAL::   Number of active cells:       865
+DEAL::   Number of degrees of freedom: 952 (by level: 4, 9, 25, 81, 289, 769, 153)
+DEAL:cg::Starting value 0.378780
+DEAL:cg::Convergence step 11 value 1.39894e-09
+DEAL::Cycle 3:
+DEAL::   Number of active cells:       1219
+DEAL::   Number of degrees of freedom: 1354 (by level: 4, 9, 25, 81, 289, 953, 277, 261)
+DEAL:cg::Starting value 0.343729
+DEAL:cg::Convergence step 13 value 6.16552e-10
+DEAL::Cycle 4:
+DEAL::   Number of active cells:       1297
+DEAL::   Number of degrees of freedom: 1446 (by level: 4, 9, 25, 81, 289, 961, 313, 349)
+DEAL:cg::Starting value 0.339440
+DEAL:cg::Convergence step 13 value 7.00850e-10

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