Move setup to build()

dealii · Jan 7, 2022 · eb4d4d5 · eb4d4d5
1 parent 5c77f46
commit eb4d4d5
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Showing 6 changed files with 59 additions and 53 deletions.
diff --git a/doc/news/changes/minor/20210309Munch b/doc/news/changes/minor/20210309Munch
@@ -1,8 +1,7 @@
-New: The classes MGLevelGlobalTransfer and MGTransferMatrixFree now
-accept in the constructor an optional function for initializing
-the internal level vectors. This is useful if one uses the the 
-transfer operators in the context of smoothers that are build
-around MatrixFree objects.
+New: The classes MGTransferMatrixFree::build() now also
+accepts an optional function for initializing the internal level vectors. 
+This is useful if one uses the the transfer operators in the context of 
+smoothers that are build around MatrixFree objects.
 <br>
 (Peter Munch, 2021/03/09)
 
diff --git a/include/deal.II/multigrid/mg_transfer.h b/include/deal.II/multigrid/mg_transfer.h
@@ -413,14 +413,6 @@ class MGLevelGlobalTransfer<LinearAlgebra::distributed::Vector<Number>>
   : public MGTransferBase<LinearAlgebra::distributed::Vector<Number>>
 {
 public:
-  /**
-   * Constructor.
-   */
-  MGLevelGlobalTransfer(
-    const std::function<void(const unsigned int,
-                             LinearAlgebra::distributed::Vector<Number> &)>
-      &initialize_dof_vector = {});
-
   /**
    * Reset the object to the state it had right after the default constructor.
    */

diff --git a/include/deal.II/multigrid/mg_transfer.templates.h b/include/deal.II/multigrid/mg_transfer.templates.h
@@ -395,16 +395,6 @@ MGLevelGlobalTransfer<VectorType>::assert_built(
 /* --------- MGLevelGlobalTransfer<LinearAlgebra::distributed::Vector> -------
  */
 
-
-template <typename Number>
-MGLevelGlobalTransfer<LinearAlgebra::distributed::Vector<Number>>::
-  MGLevelGlobalTransfer(
-    const std::function<void(const unsigned int,
-                             LinearAlgebra::distributed::Vector<Number> &)>
-      &initialize_dof_vector)
-  : initialize_dof_vector(initialize_dof_vector)
-{}
-
 template <typename Number>
 template <int dim, typename Number2, int spacedim>
 void
@@ -584,7 +574,6 @@ MGLevelGlobalTransfer<LinearAlgebra::distributed::Vector<Number>>::copy_from_mg(
       if (ghosted_level_vector[level].size() > 0)
         ghosted_vector = src[level];
 
-
       const auto ghosted_vector_ptr = (ghosted_level_vector[level].size() > 0) ?
                                         &ghosted_vector :
                                         &src[level];

diff --git a/include/deal.II/multigrid/mg_transfer_matrix_free.h b/include/deal.II/multigrid/mg_transfer_matrix_free.h
@@ -59,20 +59,13 @@ class MGTransferMatrixFree
    * Constructor without constraint matrices. Use this constructor only with
    * discontinuous finite elements or with no local refinement.
    */
-  MGTransferMatrixFree(
-    const std::function<void(const unsigned int,
-                             LinearAlgebra::distributed::Vector<Number> &)>
-      &initialize_dof_vector = {});
+  MGTransferMatrixFree();
 
   /**
    * Constructor with constraints. Equivalent to the default constructor
    * followed by initialize_constraints().
    */
-  MGTransferMatrixFree(
-    const MGConstrainedDoFs &mg_constrained_dofs,
-    const std::function<void(const unsigned int,
-                             LinearAlgebra::distributed::Vector<Number> &)>
-      &initialize_dof_vector = {});
+  MGTransferMatrixFree(const MGConstrainedDoFs &mg_constrained_dofs);
 
   /**
    * Destructor.
@@ -112,6 +105,16 @@ class MGTransferMatrixFree
           &external_partitioners =
             std::vector<std::shared_ptr<const Utilities::MPI::Partitioner>>());
 
+  /**
+   * Same as above but taking a lambda for initializing vector instead of
+   * partitioners.
+   */
+  void
+  build(const DoFHandler<dim, dim> &dof_handler,
+        const std::function<void(const unsigned int,
+                                 LinearAlgebra::distributed::Vector<Number> &)>
+          &initialize_dof_vector);
+
   /**
    * Prolongate a vector from level <tt>to_level-1</tt> to level
    * <tt>to_level</tt> using the embedding matrices of the underlying finite

diff --git a/source/multigrid/mg_transfer_matrix_free.cc b/source/multigrid/mg_transfer_matrix_free.cc
@@ -41,13 +41,8 @@ DEAL_II_NAMESPACE_OPEN
 
 
 template <int dim, typename Number>
-MGTransferMatrixFree<dim, Number>::MGTransferMatrixFree(
-  const std::function<void(const unsigned int,
-                           LinearAlgebra::distributed::Vector<Number> &)>
-    &initialize_dof_vector)
-  : MGLevelGlobalTransfer<LinearAlgebra::distributed::Vector<Number>>(
-      initialize_dof_vector)
-  , fe_degree(0)
+MGTransferMatrixFree<dim, Number>::MGTransferMatrixFree()
+  : fe_degree(0)
   , element_is_continuous(false)
   , n_components(0)
   , n_child_cell_dofs(0)
@@ -57,13 +52,8 @@ MGTransferMatrixFree<dim, Number>::MGTransferMatrixFree(
 
 template <int dim, typename Number>
 MGTransferMatrixFree<dim, Number>::MGTransferMatrixFree(
-  const MGConstrainedDoFs &mg_c,
-  const std::function<void(const unsigned int,
-                           LinearAlgebra::distributed::Vector<Number> &)>
-    &initialize_dof_vector)
-  : MGLevelGlobalTransfer<LinearAlgebra::distributed::Vector<Number>>(
-      initialize_dof_vector)
-  , fe_degree(0)
+  const MGConstrainedDoFs &mg_c)
+  : fe_degree(0)
   , element_is_continuous(false)
   , n_components(0)
   , n_child_cell_dofs(0)
@@ -103,6 +93,7 @@ MGTransferMatrixFree<dim, Number>::clear()
 }
 
 
+
 template <int dim, typename Number>
 void
 MGTransferMatrixFree<dim, Number>::build(
@@ -124,7 +115,7 @@ MGTransferMatrixFree<dim, Number>::build(
           "A initialize_dof_vector function has already been registered in the constructor!"));
 
       this->initialize_dof_vector =
-        [&external_partitioners](
+        [external_partitioners](
           const unsigned int                          level,
           LinearAlgebra::distributed::Vector<Number> &vec) {
           vec.reinit(external_partitioners[level]);
@@ -210,6 +201,39 @@ MGTransferMatrixFree<dim, Number>::build(
 
 
 
+template <int dim, typename Number>
+void
+MGTransferMatrixFree<dim, Number>::build(
+  const DoFHandler<dim, dim> &dof_handler,
+  const std::function<void(const unsigned int,
+                           LinearAlgebra::distributed::Vector<Number> &)>
+    &initialize_dof_vector)
+{
+  if (initialize_dof_vector)
+    {
+      const unsigned int n_levels =
+        dof_handler.get_triangulation().n_global_levels();
+
+      std::vector<std::shared_ptr<const Utilities::MPI::Partitioner>>
+        external_partitioners(n_levels);
+
+      for (unsigned int level = 0; level < n_levels; ++level)
+        {
+          LinearAlgebra::distributed::Vector<Number> vector;
+          initialize_dof_vector(level, vector);
+          external_partitioners[level] = vector.get_partitioner();
+        }
+
+      build(dof_handler, external_partitioners);
+    }
+  else
+    {
+      build(dof_handler);
+    }
+}
+
+
+
 template <int dim, typename Number>
 void
 MGTransferMatrixFree<dim, Number>::prolongate(

diff --git a/tests/matrix_free/multigrid_dg_sip_01.cc b/tests/matrix_free/multigrid_dg_sip_01.cc
@@ -596,12 +596,11 @@ do_test(const DoFHandler<dim> &dof, const unsigned n_q_points_1d)
   mg_constrained_dofs.initialize(dof);
   mg_constrained_dofs.make_zero_boundary_constraints(dof, {0});
 
-  MGTransferMatrixFree<dim, number> mg_transfer(
-    mg_constrained_dofs, [&](const unsigned int level, auto &vec) {
-      mg_matrices[level].initialize_dof_vector(vec);
-    });
+  MGTransferMatrixFree<dim, number> mg_transfer(mg_constrained_dofs);
 
-  mg_transfer.build(dof);
+  mg_transfer.build(dof, [&](const unsigned int level, auto &vec) {
+    mg_matrices[level].initialize_dof_vector(vec);
+  });
 
   mg::Matrix<LinearAlgebra::distributed::Vector<double>> mg_matrix(mg_matrices);