Expected output.

Author: luca-heltai

tests/fe/local_sparsity_q_iso_q1.cc

@@ -18,7 +18,9 @@
 #include <deal.II/dofs/dof_handler.h>
 #include <deal.II/dofs/dof_tools.h>
 
+#include <deal.II/fe/fe_q.h>
 #include <deal.II/fe/fe_q_iso_q1.h>
+#include <deal.II/fe/mapping_q1.h>
 
 #include <deal.II/grid/grid_generator.h>
 #include <deal.II/grid/tria.h>
@@ -45,12 +47,56 @@ test(const unsigned int n_subdivisions = 1)
   GridGenerator::hyper_cube(triangulation);
   dof_handler.distribute_dofs(fe);
 
-  DynamicSparsityPattern dsp(dof_handler.n_dofs());
-  DoFTools::make_sparsity_pattern(dof_handler, dsp);
-  sparsity_pattern.copy_from(dsp);
-
-  dsp.print(deallog.get_file_stream());
-  deallog << std::endl;
+  Triangulation<dim> triangulation_q1;
+  DoFHandler<dim>    dof_handler_q1(triangulation_q1);
+  SparsityPattern    sparsity_pattern_q1;
+  FE_Q<dim>          fe_q1(1);
+  GridGenerator::subdivided_hyper_cube(triangulation_q1, n_subdivisions);
+  dof_handler_q1.distribute_dofs(fe_q1);
+
+  std::vector<Point<dim>> support_points(dof_handler.n_dofs());
+  DoFTools::map_dofs_to_support_points(StaticMappingQ1<dim>::mapping,
+                                       dof_handler,
+                                       support_points);
+
+
+  std::vector<Point<dim>> support_points_q1(dof_handler_q1.n_dofs());
+  DoFTools::map_dofs_to_support_points(StaticMappingQ1<dim>::mapping,
+                                       dof_handler_q1,
+                                       support_points_q1);
+
+  AssertDimension(support_points.size(), support_points_q1.size());
+
+  std::vector<types::global_dof_index> new_numbers(dof_handler_q1.n_dofs());
+
+  for (unsigned int i = 0; i < support_points_q1.size(); ++i)
+    {
+      const Point<dim> &p = support_points_q1[i];
+      for (unsigned int j = 0; j < support_points.size(); ++j)
+        {
+          if (p.distance(support_points[j]) < 1e-10)
+            {
+              new_numbers[i] = j;
+              break;
+            }
+        }
+    }
+  dof_handler_q1.renumber_dofs(new_numbers);
+
+  {
+    DynamicSparsityPattern dsp(dof_handler.n_dofs());
+    DoFTools::make_sparsity_pattern(dof_handler, dsp);
+    dsp.print(deallog.get_file_stream());
+    deallog << std::endl;
+  }
+
+  {
+    DynamicSparsityPattern dsp(dof_handler_q1.n_dofs());
+    DoFTools::make_sparsity_pattern(dof_handler_q1, dsp);
+    sparsity_pattern_q1.copy_from(dsp);
+    // dsp.print(deallog.get_file_stream());
+    // deallog << std::endl;
+  }
 }