From 2210755b36f12c96c55a99f6214ef2308c38ad14 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Thu, 14 Aug 2014 07:52:59 -0500
Subject: [PATCH] Add a test that uses range-based fors.

---
 tests/deal.II/range_based_for_step-6.cc       | 358 ++++++++++++++++++
 ...6.with_cxx11=true.with_umfpack=true.output |  16 +
 2 files changed, 374 insertions(+)
 create mode 100644 tests/deal.II/range_based_for_step-6.cc
 create mode 100644 tests/deal.II/range_based_for_step-6.with_cxx11=true.with_umfpack=true.output

diff --git a/tests/deal.II/range_based_for_step-6.cc b/tests/deal.II/range_based_for_step-6.cc
new file mode 100644
index 0000000000..cec1eee680
--- /dev/null
+++ b/tests/deal.II/range_based_for_step-6.cc
@@ -0,0 +1,358 @@
+// ---------------------------------------------------------------------
+// $Id$
+//
+// Copyright (C) 2014 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.
+//
+// ---------------------------------------------------------------------
+
+
+
+// A variant of step-6 that replaces loops over cells with range-based for
+// loops a la C++11
+
+#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/lac/vector.h>
+#include <deal.II/lac/full_matrix.h>
+#include <deal.II/lac/sparse_matrix.h>
+#include <deal.II/lac/compressed_sparsity_pattern.h>
+#include <deal.II/lac/solver_cg.h>
+#include <deal.II/lac/precondition.h>
+#include <deal.II/grid/tria.h>
+#include <deal.II/dofs/dof_handler.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/grid/tria_boundary_lib.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/numerics/vector_tools.h>
+#include <deal.II/numerics/matrix_tools.h>
+#include <deal.II/numerics/data_out.h>
+
+#include <fstream>
+#include <iostream>
+
+#include <deal.II/fe/fe_q.h>
+#include <deal.II/grid/grid_out.h>
+
+
+#include <deal.II/lac/constraint_matrix.h>
+
+#include <deal.II/grid/grid_refinement.h>
+
+#include <deal.II/numerics/error_estimator.h>
+
+using namespace dealii;
+
+
+
+template <int dim>
+class Step6
+{
+public:
+  Step6 ();
+  ~Step6 ();
+
+  void run ();
+
+private:
+  void setup_system ();
+  void assemble_system ();
+  void solve ();
+  void refine_grid ();
+  void output_results (const unsigned int cycle) const;
+
+  Triangulation<dim>   triangulation;
+
+  DoFHandler<dim>      dof_handler;
+  FE_Q<dim>            fe;
+
+  ConstraintMatrix     constraints;
+
+  SparsityPattern      sparsity_pattern;
+  SparseMatrix<double> system_matrix;
+
+  Vector<double>       solution;
+  Vector<double>       system_rhs;
+};
+
+
+
+
+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 20;
+  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)
+    {
+      if (points[i].square() < 0.5*0.5)
+        values[i] = 20;
+      else
+        values[i] = 1;
+    }
+}
+
+
+
+
+template <int dim>
+Step6<dim>::Step6 ()
+  :
+  dof_handler (triangulation),
+  fe (2)
+{}
+
+
+
+template <int dim>
+Step6<dim>::~Step6 ()
+{
+  dof_handler.clear ();
+}
+
+
+
+template <int dim>
+void Step6<dim>::setup_system ()
+{
+  dof_handler.distribute_dofs (fe);
+
+  solution.reinit (dof_handler.n_dofs());
+  system_rhs.reinit (dof_handler.n_dofs());
+
+
+  constraints.clear ();
+  DoFTools::make_hanging_node_constraints (dof_handler,
+                                           constraints);
+
+
+  VectorTools::interpolate_boundary_values (dof_handler,
+                                            0,
+                                            ZeroFunction<dim>(),
+                                            constraints);
+
+
+  constraints.close ();
+
+  CompressedSparsityPattern c_sparsity(dof_handler.n_dofs());
+  DoFTools::make_sparsity_pattern(dof_handler,
+                                  c_sparsity,
+                                  constraints,
+                                  /*keep_constrained_dofs = */ false);
+
+  sparsity_pattern.copy_from(c_sparsity);
+
+  system_matrix.reinit (sparsity_pattern);
+}
+
+
+
+template <int dim>
+void Step6<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<types::global_dof_index> local_dof_indices (dofs_per_cell);
+
+  const Coefficient<dim> coefficient;
+  std::vector<double>    coefficient_values (n_q_points);
+
+  for (auto cell : dof_handler.active_cell_iterators())
+    {
+      cell_matrix = 0;
+      cell_rhs = 0;
+
+      fe_values.reinit (cell);
+
+      coefficient.value_list (fe_values.get_quadrature_points(),
+                              coefficient_values);
+
+      for (unsigned int q_index=0; q_index<n_q_points; ++q_index)
+        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_index] *
+                                   fe_values.shape_grad(i,q_index) *
+                                   fe_values.shape_grad(j,q_index) *
+                                   fe_values.JxW(q_index));
+
+            cell_rhs(i) += (fe_values.shape_value(i,q_index) *
+                            1.0 *
+                            fe_values.JxW(q_index));
+          }
+
+      cell->get_dof_indices (local_dof_indices);
+      constraints.distribute_local_to_global (cell_matrix,
+					      cell_rhs,
+					      local_dof_indices,
+					      system_matrix,
+					      system_rhs);
+    }
+}
+
+
+
+
+template <int dim>
+void Step6<dim>::solve ()
+{
+  SolverControl      solver_control (1000, 1e-12);
+  SolverCG<>         solver (solver_control);
+
+  PreconditionSSOR<> preconditioner;
+  preconditioner.initialize(system_matrix, 1.2);
+
+  solver.solve (system_matrix, solution, system_rhs,
+                preconditioner);
+
+  constraints.distribute (solution);
+}
+
+
+
+template <int dim>
+void Step6<dim>::refine_grid ()
+{
+  Vector<float> estimated_error_per_cell (triangulation.n_active_cells());
+
+  KellyErrorEstimator<dim>::estimate (dof_handler,
+                                      QGauss<dim-1>(3),
+                                      typename FunctionMap<dim>::type(),
+                                      solution,
+                                      estimated_error_per_cell);
+
+  GridRefinement::refine_and_coarsen_fixed_number (triangulation,
+                                                   estimated_error_per_cell,
+                                                   0.3, 0.03);
+
+  triangulation.execute_coarsening_and_refinement ();
+}
+
+
+
+template <int dim>
+void Step6<dim>::output_results (const unsigned int cycle) const
+{
+  Assert (cycle < 10, ExcNotImplemented());
+
+  std::string filename = "grid-";
+  filename += ('0' + cycle);
+  filename += ".eps";
+
+  std::ofstream output (filename.c_str());
+
+  GridOut grid_out;
+  grid_out.write_eps (triangulation, output);
+}
+
+
+
+template <int dim>
+void Step6<dim>::run ()
+{
+  for (unsigned int cycle=0; cycle<3; ++cycle)
+    {
+      deallog << "Cycle " << cycle << ':' << std::endl;
+
+      if (cycle == 0)
+        {
+          GridGenerator::hyper_ball (triangulation);
+
+          static const HyperBallBoundary<dim> boundary;
+          triangulation.set_boundary (0, boundary);
+
+          triangulation.refine_global (1);
+        }
+      else
+        refine_grid ();
+
+
+      deallog << "   Number of active cells:       "
+                << triangulation.n_active_cells()
+                << std::endl;
+
+      setup_system ();
+
+      deallog << "   Number of degrees of freedom: "
+                << dof_handler.n_dofs()
+                << std::endl;
+
+      assemble_system ();
+      solve ();
+    }
+}
+
+
+
+int main ()
+{
+  std::ofstream logfile ("output");
+  deallog << std::setprecision (3);
+
+  deallog.attach(logfile);
+  deallog.depth_console (0);
+  deallog.threshold_double(1.e-7);
+
+  Step6<2> laplace_problem_2d;
+  laplace_problem_2d.run ();
+}
diff --git a/tests/deal.II/range_based_for_step-6.with_cxx11=true.with_umfpack=true.output b/tests/deal.II/range_based_for_step-6.with_cxx11=true.with_umfpack=true.output
new file mode 100644
index 0000000000..1add5861bd
--- /dev/null
+++ b/tests/deal.II/range_based_for_step-6.with_cxx11=true.with_umfpack=true.output
@@ -0,0 +1,16 @@
+
+DEAL::Cycle 0:
+DEAL::   Number of active cells:       20
+DEAL::   Number of degrees of freedom: 89
+DEAL:cg::Starting value 0.352
+DEAL:cg::Convergence step 22 value 0
+DEAL::Cycle 1:
+DEAL::   Number of active cells:       44
+DEAL::   Number of degrees of freedom: 209
+DEAL:cg::Starting value 0.271
+DEAL:cg::Convergence step 30 value 0
+DEAL::Cycle 2:
+DEAL::   Number of active cells:       92
+DEAL::   Number of degrees of freedom: 449
+DEAL:cg::Starting value 0.204
+DEAL:cg::Convergence step 51 value 0
-- 
2.39.5