Add parallel test for find_active_cell_around_point

tests/bits/point_value_03.cc

@@ -0,0 +1,211 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2004 - 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.
+//
+// ---------------------------------------------------------------------
+
+
+// check VectorTools::point_value
+// This test is the parallel version of point_value_01
+
+
+
+#include <deal.II/base/conditional_ostream.h>
+#include <deal.II/base/function_lib.h>
+#include <deal.II/base/quadrature_lib.h>
+
+#include <deal.II/distributed/tria.h>
+
+#include <deal.II/dofs/dof_handler.h>
+#include <deal.II/dofs/dof_tools.h>
+
+#include <deal.II/fe/fe_q.h>
+
+#include <deal.II/grid/grid_generator.h>
+#include <deal.II/grid/grid_tools.h>
+#include <deal.II/grid/grid_tools_cache.h>
+#include <deal.II/grid/tria.h>
+#include <deal.II/grid/tria_accessor.h>
+#include <deal.II/grid/tria_iterator.h>
+
+#include <deal.II/lac/generic_linear_algebra.h>
+#include <deal.II/lac/vector.h>
+
+#include <deal.II/numerics/vector_tools.h>
+
+#include "../tests.h"
+
+
+using VectorType = LinearAlgebra::distributed::Vector<double>;
+
+template <int dim>
+class MySquareFunction : public Function<dim, VectorType::value_type>
+{
+public:
+  MySquareFunction()
+    : Function<dim, VectorType::value_type>()
+  {}
+
+  virtual VectorType::value_type
+  value(const Point<dim> &p, const unsigned int component = 0) const
+  {
+    return (component + 1) * p.square() + 1;
+  }
+
+  virtual void
+  vector_value(const Point<dim> &              p,
+               Vector<VectorType::value_type> &values) const
+  {
+    values(0) = value(p, 0);
+  }
+};
+
+
+template <int dim>
+class MyExpFunction : public Function<dim>
+{
+public:
+  MyExpFunction()
+    : Function<dim>()
+  {}
+
+  virtual double
+  value(const Point<dim> &p, const unsigned int component) const
+  {
+    return std::exp(p(0));
+  }
+
+  virtual void
+  vector_value(const Point<dim> &p, Vector<double> &values) const
+  {
+    values(0) = value(p, 0);
+  }
+};
+
+
+
+template <int dim>
+void
+make_mesh(Triangulation<dim> &tria)
+{
+  GridGenerator::hyper_cube(tria, -1, 1);
+
+  // refine the mesh in a random way so as to
+  // generate as many cells with
+  // hanging nodes as possible
+  tria.refine_global(4 - dim);
+  const double steps[4] = {/*d=0*/ 0, 7, 3, 3};
+  for (unsigned int i = 0; i < steps[dim]; ++i)
+    {
+      typename Triangulation<dim>::active_cell_iterator cell =
+        tria.begin_active();
+      for (unsigned int index = 0; cell != tria.end(); ++cell, ++index)
+        if (index % (3 * dim) == 0)
+          cell->set_refine_flag();
+      tria.execute_coarsening_and_refinement();
+    }
+}
+
+
+
+template <int dim>
+void
+check()
+{
+  parallel::distributed::Triangulation<dim> tria(MPI_COMM_WORLD);
+  make_mesh(tria);
+
+  FE_Q<dim>       element(QIterated<1>(QTrapez<1>(), 3));
+  DoFHandler<dim> dof(tria);
+  dof.distribute_dofs(element);
+
+  static const MySquareFunction<dim> function;
+
+  VectorType v;
+
+  const IndexSet locally_owned_dofs = dof.locally_owned_dofs();
+  const IndexSet locally_relevant_dofs =
+    DoFTools::extract_locally_relevant_dofs(dof);
+
+  v.reinit(locally_owned_dofs, locally_relevant_dofs, MPI_COMM_WORLD);
+  VectorTools::interpolate(dof, function, v);
+  v.update_ghost_values();
+
+  // v = 1.;
+
+  // for the following points, check the
+  // function value, output it, and
+  // verify that the value retrieved from
+  // the interpolated function is close
+  // enough to that of the real function
+  //
+  // also verify that the actual value is
+  // roughly correct
+  Point<dim> p[3];
+  for (unsigned int d = 0; d < dim; ++d)
+    {
+      p[0][d] = 0;
+      p[1][d] = 0.5;
+      p[2][d] = 1. / 3.;
+    }
+  Vector<VectorType::value_type> value(1);
+  const auto &                   mapping = get_default_linear_mapping(tria);
+  for (unsigned int i = 0; i < 3; ++i)
+    {
+      {
+        bool point_in_locally_owned_cell = false;
+        value(0)                         = 0;
+        {
+          auto cell_and_ref_point =
+            GridTools::find_active_cell_around_point(mapping, dof, p[i]);
+          if (cell_and_ref_point.first.state() == IteratorState::valid)
+            {
+              point_in_locally_owned_cell =
+                cell_and_ref_point.first->is_locally_owned();
+            }
+        }
+        if (point_in_locally_owned_cell)
+          {
+            VectorTools::point_value(mapping, dof, v, p[i], value);
+          }
+      }
+      value(0) = Utilities::MPI::sum(value(0), MPI_COMM_WORLD);
+      deallog << -value(0) << std::endl;
+      std::cout << value(0) << std::endl;
+
+      Assert(std::abs(value(0) - function.value(p[i])) < 2e-4,
+             ExcInternalError());
+    }
+
+  deallog << "OK" << std::endl;
+}
+
+
+int
+main(int argc, char **argv)
+{
+  Utilities::MPI::MPI_InitFinalize mpi_initialization(argc, argv, 1);
+
+  MPI_Comm mpi_communicator = MPI_COMM_WORLD;
+
+
+  MPILogInitAll log;
+
+  deallog << std::setprecision(4);
+
+  deallog.push("2d");
+  check<2>();
+  deallog.pop();
+  deallog.push("3d");
+  check<3>();
+  deallog.pop();
+}

tests/bits/point_value_03.mpirun=1.output

@@ -0,0 +1,9 @@
+
+DEAL:0:2d::-1.000
+DEAL:0:2d::-1.500
+DEAL:0:2d::-1.222
+DEAL:0:2d::OK
+DEAL:0:3d::-1.000
+DEAL:0:3d::-1.750
+DEAL:0:3d::-1.333
+DEAL:0:3d::OK

tests/bits/point_value_03.mpirun=7.output

@@ -0,0 +1,69 @@
+
+DEAL:0:2d::-1.000
+DEAL:0:2d::-1.500
+DEAL:0:2d::-1.222
+DEAL:0:2d::OK
+DEAL:0:3d::-1.000
+DEAL:0:3d::-1.750
+DEAL:0:3d::-1.333
+DEAL:0:3d::OK
+
+DEAL:1:2d::-1.000
+DEAL:1:2d::-1.500
+DEAL:1:2d::-1.222
+DEAL:1:2d::OK
+DEAL:1:3d::-1.000
+DEAL:1:3d::-1.750
+DEAL:1:3d::-1.333
+DEAL:1:3d::OK
+
+
+DEAL:2:2d::-1.000
+DEAL:2:2d::-1.500
+DEAL:2:2d::-1.222
+DEAL:2:2d::OK
+DEAL:2:3d::-1.000
+DEAL:2:3d::-1.750
+DEAL:2:3d::-1.333
+DEAL:2:3d::OK
+
+
+DEAL:3:2d::-1.000
+DEAL:3:2d::-1.500
+DEAL:3:2d::-1.222
+DEAL:3:2d::OK
+DEAL:3:3d::-1.000
+DEAL:3:3d::-1.750
+DEAL:3:3d::-1.333
+DEAL:3:3d::OK
+
+
+DEAL:4:2d::-1.000
+DEAL:4:2d::-1.500
+DEAL:4:2d::-1.222
+DEAL:4:2d::OK
+DEAL:4:3d::-1.000
+DEAL:4:3d::-1.750
+DEAL:4:3d::-1.333
+DEAL:4:3d::OK
+
+
+DEAL:5:2d::-1.000
+DEAL:5:2d::-1.500
+DEAL:5:2d::-1.222
+DEAL:5:2d::OK
+DEAL:5:3d::-1.000
+DEAL:5:3d::-1.750
+DEAL:5:3d::-1.333
+DEAL:5:3d::OK
+
+
+DEAL:6:2d::-1.000
+DEAL:6:2d::-1.500
+DEAL:6:2d::-1.222
+DEAL:6:2d::OK
+DEAL:6:3d::-1.000
+DEAL:6:3d::-1.750
+DEAL:6:3d::-1.333
+DEAL:6:3d::OK
+