Added missing documentation, plus some missing ierr's and indentend

diff --git a/include/deal.II/lac/petsc_precondition.h b/include/deal.II/lac/petsc_precondition.h
index 7a27046a8ef5a71a644ed42c1b96e538d6198d5d..20a2c3a18200f1e75851292d70f93c18b4b2199b 100644 (file)
--- a/include/deal.II/lac/petsc_precondition.h
+++ b/include/deal.II/lac/petsc_precondition.h
@@ -959,7 +959,18 @@ namespace PETScWrappers
 
   /**
    * A class that implements the interface to use the BDDC preconditioner from
-   * PETSc.
+   * PETSc (<a
+   * href="https://petsc.org/release/docs/manualpages/PC/PCBDDC.html">PCBDDC</a>),
+   * which is a two-level, substructuring, non-overlapping domain decomposition
+   * preconditioner. Details of the implementation can be found in "S Zampini,
+   * SISC (2016)". It mainly consists of two elements:
+   *
+   * <ul>
+   *   <li> Local solvers: Solvers for each subdomain. These are performed concurrently by each processor
+   *   <li> A coarse solver: Continuity between each subdomain is imposed in a small number of DoFs, referred to as <em>primal DoFs</em>. This solver solves such problem.
+   * </ul>
+   *
+   * The size of the primal space is determined through the @p AdditionalData parameters.
    *
    * @ingroup PETScWrappers
    */
@@ -977,28 +988,30 @@ namespace PETScWrappers
        * than what is exposed here.
        */
       AdditionalData(const bool                    use_vertices = true,
-                     const bool                    use_edges_    = false,
-                     const bool                    use_faces_    = false,
-                     const bool                    symmetric_    = false,
-                     const unsigned int            coords_cdim_  = 0,
-                     const types::global_dof_index coords_n_     = 0,
-                     const PetscReal *             coords_data_  = nullptr);
+                     const bool                    use_edges_   = false,
+                     const bool                    use_faces_   = false,
+                     const bool                    symmetric_   = false,
+                     const unsigned int            coords_cdim_ = 0,
+                     const types::global_dof_index coords_n_    = 0,
+                     const PetscReal *             coords_data_ = nullptr);
 
       /**
        * This flag sets the use of degrees of freedom in the vertices of the
-       * subdomain as primal variables.
+       * subdomains as primal variables for the creation of the coarse space.
        */
       bool use_vertices;
 
       /**
        * This flag sets the use of degrees of freedom in the edges of the
-       * subdomain as primal variables.
+       * subdomain as primal variables for the creation of the coarse space.
+       * Continuity is actually imposed at the edge average.
        */
       bool use_edges;
 
       /**
        * This flag sets the use of degrees of freedom in the faces of the
-       * subdomain as primal variables.
+       * subdomain as primal variables for the creation of the coarse space.
+       * Continuity is actually imposed at the face average.
        */
       bool use_faces;
 
@@ -1008,12 +1021,21 @@ namespace PETScWrappers
       bool symmetric;
 
       /**
-       * Support for H1 problems
+       * Set the number of coordinates that each DoF has, i.e. 2 in 2D and 3 in
+       * 3D.
+       */
+      unsigned int coords_cdim;
+
+      /**
+       * Set the number of degrees of freedom that the problem has.
        */
-      unsigned int            coords_cdim;
       types::global_dof_index coords_n;
-      const PetscReal
-        *coords_data; /* not referenced, consumed at initialize time */
+
+      /**
+       * Set the location of each DoF. This helps in improving the definition of
+       * the vertices for unstructured meshes.
+       */
+      const PetscReal *coords_data;
     };
 
     /**

diff --git a/source/lac/petsc_parallel_sparse_matrix.cc b/source/lac/petsc_parallel_sparse_matrix.cc
index fb7bc57667d5af461dcc82fce2e5d4db42beb801..fcc2576b6c3c4e62d09fd018372816338d19aa6c 100644 (file)
--- a/source/lac/petsc_parallel_sparse_matrix.cc
+++ b/source/lac/petsc_parallel_sparse_matrix.cc
@@ -473,6 +473,7 @@ namespace PETScWrappers
             std::to_string(col_owners) + ")"));
       }
 #  endif
+      PetscErrorCode ierr;
 
       // create the local to global mappings as arrays.
       IndexSet::size_type n_l2g_row = local_active_rows.n_elements();
@@ -493,39 +494,51 @@ namespace PETScWrappers
       IS is_glob_row, is_glob_col;
       // Create row index set
       ISLocalToGlobalMapping l2gmap_row;
-      ISCreateGeneral(communicator,
-                      n_l2g_row,
-                      idx_glob_row.data(),
-                      PETSC_COPY_VALUES,
-                      &is_glob_row);
-      ISLocalToGlobalMappingCreateIS(is_glob_row, &l2gmap_row);
-      ISDestroy(&is_glob_row);
-      ISLocalToGlobalMappingViewFromOptions(l2gmap_row, NULL, "-view_map");
+      ierr = ISCreateGeneral(communicator,
+                             n_l2g_row,
+                             idx_glob_row.data(),
+                             PETSC_COPY_VALUES,
+                             &is_glob_row);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr = ISLocalToGlobalMappingCreateIS(is_glob_row, &l2gmap_row);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr = ISDestroy(&is_glob_row);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr =
+        ISLocalToGlobalMappingViewFromOptions(l2gmap_row, NULL, "-view_map");
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
 
       // Create column index set
       ISLocalToGlobalMapping l2gmap_col;
-      ISCreateGeneral(communicator,
-                      n_l2g_col,
-                      idx_glob_col.data(),
-                      PETSC_COPY_VALUES,
-                      &is_glob_col);
-      ISLocalToGlobalMappingCreateIS(is_glob_col, &l2gmap_col);
-      ISDestroy(&is_glob_col);
-      ISLocalToGlobalMappingViewFromOptions(l2gmap_col, NULL, "-view_map");
+      ierr = ISCreateGeneral(communicator,
+                             n_l2g_col,
+                             idx_glob_col.data(),
+                             PETSC_COPY_VALUES,
+                             &is_glob_col);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr = ISLocalToGlobalMappingCreateIS(is_glob_col, &l2gmap_col);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr = ISDestroy(&is_glob_col);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr =
+        ISLocalToGlobalMappingViewFromOptions(l2gmap_col, NULL, "-view_map");
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
 
       // create the matrix with the IS constructor.
-      PetscErrorCode ierr = MatCreateIS(communicator,
-                                        1,
-                                        local_rows.n_elements(),
-                                        local_columns.n_elements(),
-                                        sparsity_pattern.n_rows(),
-                                        sparsity_pattern.n_cols(),
-                                        l2gmap_row,
-                                        l2gmap_col,
-                                        &matrix);
-      AssertThrow(ierr == 0, ExcPETScError(ierr));
-      ISLocalToGlobalMappingDestroy(&l2gmap_row);
-      ISLocalToGlobalMappingDestroy(&l2gmap_col);
+      ierr = MatCreateIS(communicator,
+                         1,
+                         local_rows.n_elements(),
+                         local_columns.n_elements(),
+                         sparsity_pattern.n_rows(),
+                         sparsity_pattern.n_cols(),
+                         l2gmap_row,
+                         l2gmap_col,
+                         &matrix);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr = ISLocalToGlobalMappingDestroy(&l2gmap_row);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr = ISLocalToGlobalMappingDestroy(&l2gmap_col);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
 
       // next preset the exact given matrix
       // entries with zeros. This doesn't avoid any
@@ -542,10 +555,12 @@ namespace PETScWrappers
 
       // In the MATIS case, we use the local matrix instead
       Mat local_matrix;
-      MatISGetLocalMat(matrix, &local_matrix);
-      MatSetType(local_matrix,
-                 MATSEQAIJ); // SEQ as it is local! TODO: Allow for OpenMP
-                             // parallelization in local node.
+      ierr = MatISGetLocalMat(matrix, &local_matrix);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
+      ierr = MatSetType(local_matrix,
+                        MATSEQAIJ); // SEQ as it is local! TODO: Allow for
+                                    // OpenMP parallelization in local node.
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
       if (local_rows.n_elements() > 0)
         {
           // MatSEQAIJSetPreallocationCSR
@@ -621,7 +636,8 @@ namespace PETScWrappers
         close_matrix(local_matrix);
         set_keep_zero_rows(local_matrix);
       }
-      MatISRestoreLocalMat(matrix, &local_matrix);
+      ierr = MatISRestoreLocalMat(matrix, &local_matrix);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
     }
 
 #  ifndef DOXYGEN

diff --git a/source/lac/petsc_precondition.cc b/source/lac/petsc_precondition.cc
index aa2cd5caf9d2481da878f5cbe7a0c2264e35d569..f78ece4248574660374acda1b4528faeefc5c8f2 100644 (file)
--- a/source/lac/petsc_precondition.cc
+++ b/source/lac/petsc_precondition.cc
@@ -892,7 +892,6 @@ namespace PETScWrappers
     PetscErrorCode ierr = PCSetType(pc, const_cast<char *>(PCBDDC));
     AssertThrow(ierr == 0, ExcPETScError(ierr));
 
-    // TODO: Add BDDC options, in particular the additional primal nodes
     std::stringstream ssStream;
 
     if (additional_data.use_vertices)
@@ -911,7 +910,8 @@ namespace PETScWrappers
       set_option_value("-pc_bddc_symmetric", "true");
     else
       set_option_value("-pc_bddc_symmetric", "false");
-    if (additional_data.coords_cdim)
+    if (additional_data.coords_cdim && additional_data.coords_n &&
+        additional_data.coords_data)
       {
         set_option_value("-pc_bddc_corner_selection", "true");
         ierr = PCSetCoordinates(pc,