From 8639dd7c6695d4e79fe079ada74cd4506742cdc7 Mon Sep 17 00:00:00 2001
From: bangerth <bangerth@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Wed, 21 Nov 2012 23:49:38 +0000
Subject: [PATCH] Introduce a version of step-40 that uses a direct solver.

git-svn-id: https://svn.dealii.org/trunk@27667 0785d39b-7218-0410-832d-ea1e28bc413d
---
 tests/mpi/step-40_direct_solver.cc            | 381 ++++++++++++++++++
 .../step-40_direct_solver/ncpu_10/cmp/generic |  17 +
 .../step-40_direct_solver/ncpu_3/cmp/generic  |  17 +
 .../step-40_direct_solver/ncpu_4/cmp/generic  |  17 +
 4 files changed, 432 insertions(+)
 create mode 100644 tests/mpi/step-40_direct_solver.cc
 create mode 100644 tests/mpi/step-40_direct_solver/ncpu_10/cmp/generic
 create mode 100644 tests/mpi/step-40_direct_solver/ncpu_3/cmp/generic
 create mode 100644 tests/mpi/step-40_direct_solver/ncpu_4/cmp/generic

diff --git a/tests/mpi/step-40_direct_solver.cc b/tests/mpi/step-40_direct_solver.cc
new file mode 100644
index 0000000000..f9d0d46c68
--- /dev/null
+++ b/tests/mpi/step-40_direct_solver.cc
@@ -0,0 +1,381 @@
+//---------------------------------------------------------------------------
+//    $Id$
+//    Version: $Name$
+//
+//    Copyright (C) 2009, 2012 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.
+//
+//---------------------------------------------------------------------------
+
+// A lightly adapted version of the step-40 tutorial program
+
+#include "../tests.h"
+#include <deal.II/base/quadrature_lib.h>
+#include <deal.II/base/function.h>
+#include <deal.II/base/mpi.h>
+#include <deal.II/lac/vector.h>
+#include <deal.II/lac/full_matrix.h>
+#include <deal.II/lac/solver_cg.h>
+#include <deal.II/lac/constraint_matrix.h>
+#include <deal.II/lac/compressed_simple_sparsity_pattern.h>
+
+#include <deal.II/lac/petsc_parallel_sparse_matrix.h>
+#include <deal.II/lac/petsc_parallel_vector.h>
+#include <deal.II/lac/petsc_solver.h>
+#include <deal.II/lac/petsc_precondition.h>
+
+#include <deal.II/grid/grid_generator.h>
+#include <deal.II/grid/tria_accessor.h>
+#include <deal.II/grid/tria_iterator.h>
+#include <deal.II/dofs/dof_handler.h>
+#include <deal.II/dofs/dof_accessor.h>
+#include <deal.II/dofs/dof_tools.h>
+#include <deal.II/fe/fe_values.h>
+#include <deal.II/fe/fe_q.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/utilities.h>
+#include <deal.II/base/conditional_ostream.h>
+#include <deal.II/base/index_set.h>
+#include <deal.II/lac/sparsity_tools.h>
+#include <deal.II/distributed/tria.h>
+#include <deal.II/distributed/grid_refinement.h>
+
+#include <fstream>
+#include <iostream>
+
+namespace Step40
+{
+  using namespace dealii;
+
+
+  template <int dim>
+  class LaplaceProblem
+  {
+    public:
+      LaplaceProblem ();
+      ~LaplaceProblem ();
+
+      void run ();
+
+    private:
+      void setup_system ();
+      void assemble_system ();
+      void solve ();
+      void refine_grid ();
+
+      MPI_Comm mpi_communicator;
+
+      parallel::distributed::Triangulation<dim>   triangulation;
+
+      DoFHandler<dim>      dof_handler;
+      FE_Q<dim>            fe;
+
+      IndexSet             locally_owned_dofs;
+      IndexSet             locally_relevant_dofs;
+
+      ConstraintMatrix     constraints;
+
+      PETScWrappers::MPI::SparseMatrix system_matrix;
+      PETScWrappers::MPI::Vector locally_relevant_solution;
+      PETScWrappers::MPI::Vector system_rhs;
+
+      ConditionalOStream                pcout;
+  };
+
+
+
+
+  template <int dim>
+  LaplaceProblem<dim>::LaplaceProblem ()
+                  :
+                  mpi_communicator (MPI_COMM_WORLD),
+                  triangulation (mpi_communicator,
+                                 typename Triangulation<dim>::MeshSmoothing
+                                 (Triangulation<dim>::smoothing_on_refinement |
+                                  Triangulation<dim>::smoothing_on_coarsening)),
+                  dof_handler (triangulation),
+                  fe (2),
+                  pcout (Utilities::MPI::this_mpi_process(mpi_communicator)
+                          == 0
+			 ?
+			 deallog.get_file_stream()
+			 :
+			 std::cout,
+                         (Utilities::MPI::this_mpi_process(mpi_communicator)
+                          == 0))
+  {}
+
+
+
+  template <int dim>
+  LaplaceProblem<dim>::~LaplaceProblem ()
+  {
+    dof_handler.clear ();
+  }
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::setup_system ()
+  {
+    dof_handler.distribute_dofs (fe);
+
+    locally_owned_dofs = dof_handler.locally_owned_dofs ();
+    DoFTools::extract_locally_relevant_dofs (dof_handler,
+                                             locally_relevant_dofs);
+
+    locally_relevant_solution.reinit (mpi_communicator,
+                                      locally_owned_dofs,
+                                      locally_relevant_dofs);
+    locally_relevant_solution = 0;
+    system_rhs.reinit (mpi_communicator,
+                       dof_handler.n_dofs(),
+                       dof_handler.n_locally_owned_dofs());
+    system_rhs = 0;
+
+    constraints.clear ();
+    constraints.reinit (locally_relevant_dofs);
+    DoFTools::make_hanging_node_constraints (dof_handler, constraints);
+    VectorTools::interpolate_boundary_values (dof_handler,
+                                              0,
+                                              ZeroFunction<dim>(),
+                                              constraints);
+    constraints.close ();
+
+    CompressedSimpleSparsityPattern csp (dof_handler.n_dofs(),
+                                         dof_handler.n_dofs(),
+                                         locally_relevant_dofs);
+    DoFTools::make_sparsity_pattern (dof_handler,
+                                     csp,
+                                     constraints, false);
+    SparsityTools::distribute_sparsity_pattern (csp,
+                                                dof_handler.n_locally_owned_dofs_per_processor(),
+                                                mpi_communicator,
+                                                locally_relevant_dofs);
+    system_matrix.reinit (mpi_communicator,
+                          csp,
+                          dof_handler.n_locally_owned_dofs_per_processor(),
+                          dof_handler.n_locally_owned_dofs_per_processor(),
+                          Utilities::MPI::this_mpi_process(mpi_communicator));
+  }
+
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::assemble_system ()
+  {
+    const QGauss<dim>  quadrature_formula(3);
+
+    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<unsigned int> local_dof_indices (dofs_per_cell);
+
+    typename DoFHandler<dim>::active_cell_iterator
+      cell = dof_handler.begin_active(),
+      endc = dof_handler.end();
+    for (; cell!=endc; ++cell)
+      if (cell->is_locally_owned())
+        {
+          cell_matrix = 0;
+          cell_rhs = 0;
+
+          fe_values.reinit (cell);
+
+          for (unsigned int q_point=0; q_point<n_q_points; ++q_point)
+            {
+              const double
+                rhs_value
+                = (fe_values.quadrature_point(q_point)[1]
+                   >
+                   0.5+0.25*std::sin(4.0 * numbers::PI *
+                                     fe_values.quadrature_point(q_point)[0])
+                   ? 1 : -1);
+
+              for (unsigned int i=0; i<dofs_per_cell; ++i)
+                {
+                  for (unsigned int j=0; j<dofs_per_cell; ++j)
+                    cell_matrix(i,j) += (fe_values.shape_grad(i,q_point) *
+                                         fe_values.shape_grad(j,q_point) *
+                                         fe_values.JxW(q_point));
+
+                  cell_rhs(i) += (rhs_value *
+                                  fe_values.shape_value(i,q_point) *
+                                  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 ();
+    system_rhs.compress ();
+  }
+
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::solve ()
+  {
+    PETScWrappers::MPI::Vector
+      completely_distributed_solution (mpi_communicator,
+                                       dof_handler.n_dofs(),
+                                       dof_handler.n_locally_owned_dofs());
+
+    SolverControl solver_control (dof_handler.n_dofs(), 1e-12);
+    PETScWrappers::SparseDirectMUMPS solver(solver_control, mpi_communicator);
+    solver.set_symmetric_mode(true);
+    solver.solve(system_matrix, completely_distributed_solution, system_rhs);
+
+    pcout << "   Solved in " << solver_control.last_step()
+          << " iterations." << std::endl;
+
+    constraints.distribute (completely_distributed_solution);
+
+    locally_relevant_solution = completely_distributed_solution;
+    locally_relevant_solution.update_ghost_values();
+  }
+
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::refine_grid ()
+  {
+    triangulation.refine_global (1);
+  }
+
+
+
+
+  template <int dim>
+  void LaplaceProblem<dim>::run ()
+  {
+    const unsigned int n_cycles = 2;
+    for (unsigned int cycle=0; cycle<n_cycles; ++cycle)
+      {
+        pcout << "Cycle " << cycle << ':' << std::endl;
+
+        if (cycle == 0)
+          {
+            GridGenerator::hyper_cube (triangulation);
+            triangulation.refine_global (5);
+          }
+        else
+          refine_grid ();
+
+        setup_system ();
+
+        pcout << "   Number of active cells:       "
+              << triangulation.n_global_active_cells()
+              << std::endl
+	      << "      ";
+	for (unsigned int i=0; i<Utilities::MPI::n_mpi_processes(mpi_communicator); ++i)
+	  pcout << triangulation.n_locally_owned_active_cells_per_processor()[i]
+		<< '+';
+	pcout << std::endl;
+
+	pcout << "   Number of degrees of freedom: "
+              << dof_handler.n_dofs()
+              << std::endl
+	      << "      ";
+	for (unsigned int i=0; i<Utilities::MPI::n_mpi_processes(mpi_communicator); ++i)
+	  pcout << dof_handler.n_locally_owned_dofs_per_processor()[i]
+		<< '+';
+	pcout << std::endl;
+
+        assemble_system ();
+        solve ();
+
+        pcout << std::endl;
+      }
+  }
+}
+
+
+int test_mpi ()
+{
+
+  try
+    {
+      using namespace dealii;
+      using namespace Step40;
+
+      deallog.depth_console (0);
+
+      {
+        LaplaceProblem<2> laplace_problem_2d;
+        laplace_problem_2d.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;
+
+      return 1;
+    }
+  catch (...)
+    {
+      std::cerr << std::endl << std::endl
+                << "----------------------------------------------------"
+                << std::endl;
+      std::cerr << "Unknown exception!" << std::endl
+                << "Aborting!" << std::endl
+                << "----------------------------------------------------"
+                << std::endl;
+      return 1;
+    }
+
+  return 0;
+}
+
+
+
+
+int main(int argc, char *argv[])
+{
+  Utilities::MPI::MPI_InitFinalize mpi (argc, argv);
+
+  if (Utilities::MPI::this_mpi_process (MPI_COMM_WORLD) == 0)
+    {
+      std::ofstream logfile(output_file_for_mpi("step-40_direct_solver").c_str());
+      deallog.attach(logfile);
+      deallog.depth_console(0);
+      deallog.threshold_double(1.e-10);
+
+      deallog.push("mpi");
+      test_mpi();
+      deallog.pop();
+    }
+  else
+    test_mpi();
+}
diff --git a/tests/mpi/step-40_direct_solver/ncpu_10/cmp/generic b/tests/mpi/step-40_direct_solver/ncpu_10/cmp/generic
new file mode 100644
index 0000000000..d51e49e6a9
--- /dev/null
+++ b/tests/mpi/step-40_direct_solver/ncpu_10/cmp/generic
@@ -0,0 +1,17 @@
+
+Cycle 0:
+   Number of active cells:       1024
+      104+100+104+100+104+104+100+104+100+104+
+   Number of degrees of freedom: 4225
+      465+416+432+416+416+432+416+416+400+416+
+DEAL:mpi::Convergence step 1 value 0
+   Solved in 1 iterations.
+
+Cycle 1:
+   Number of active cells:       4096
+      408+412+408+412+408+408+412+408+412+408+
+   Number of degrees of freedom: 16641
+      1729+1680+1664+1680+1632+1664+1680+1632+1648+1632+
+DEAL:mpi::Convergence step 1 value 0
+   Solved in 1 iterations.
+
diff --git a/tests/mpi/step-40_direct_solver/ncpu_3/cmp/generic b/tests/mpi/step-40_direct_solver/ncpu_3/cmp/generic
new file mode 100644
index 0000000000..e0df3dbc63
--- /dev/null
+++ b/tests/mpi/step-40_direct_solver/ncpu_3/cmp/generic
@@ -0,0 +1,17 @@
+
+Cycle 0:
+   Number of active cells:       1024
+      340+344+340+
+   Number of degrees of freedom: 4225
+      1453+1412+1360+
+DEAL:mpi::Convergence step 1 value 0
+   Solved in 1 iterations.
+
+Cycle 1:
+   Number of active cells:       4096
+      1364+1368+1364+
+   Number of degrees of freedom: 16641
+      5645+5540+5456+
+DEAL:mpi::Convergence step 1 value 0
+   Solved in 1 iterations.
+
diff --git a/tests/mpi/step-40_direct_solver/ncpu_4/cmp/generic b/tests/mpi/step-40_direct_solver/ncpu_4/cmp/generic
new file mode 100644
index 0000000000..7cee1ea8b3
--- /dev/null
+++ b/tests/mpi/step-40_direct_solver/ncpu_4/cmp/generic
@@ -0,0 +1,17 @@
+
+Cycle 0:
+   Number of active cells:       1024
+      256+256+256+256+
+   Number of degrees of freedom: 4225
+      1089+1056+1056+1024+
+DEAL:mpi::Convergence step 1 value 0
+   Solved in 1 iterations.
+
+Cycle 1:
+   Number of active cells:       4096
+      1024+1024+1024+1024+
+   Number of degrees of freedom: 16641
+      4225+4160+4160+4096+
+DEAL:mpi::Convergence step 1 value 0
+   Solved in 1 iterations.
+
-- 
2.39.5