allow for empty flux matrix

git-svn-id: https://svn.dealii.org/trunk@12659 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/deal.II/source/dofs/dof_tools.cc b/deal.II/deal.II/source/dofs/dof_tools.cc
index f9a9b078d5f56821e20f82fbdad92da9430e9b8e..1afc6be665512f2ba430a0af8a0ca28d0caa6116 100644 (file)
--- a/deal.II/deal.II/source/dofs/dof_tools.cc
+++ b/deal.II/deal.II/source/dofs/dof_tools.cc
@@ -413,7 +413,8 @@ compute_cell_row_length_matrix(
                    {
                      const unsigned int jblock = fe.first_block_of_base(base) + mult;
                      if (couple_cell(iblock, jblock) != DoFTools::none ||
-                         couple_face(iblock, jblock) != DoFTools::none)
+                         (couple_face.size(0) != 0 &&
+                          couple_face(iblock, jblock) != DoFTools::none))
                        {
                          matrix(i, jblock) += increment;
                        }
@@ -440,44 +441,46 @@ compute_face_row_length_matrix(
                                   // This function will be called
                                   // once per face, at the refinement
                                   // edge from a refined cell.
+
+                                  // Compute contributions due to
+                                  // numerical fluxes.
+  if (couple_face.size(0) != 0)
+    for (unsigned int base=0;base<nfe.n_base_elements();++base)
+      {
+       const unsigned int increment = nfe.base_element(base).dofs_per_cell
+                                      - nfe.base_element(base).dofs_per_face;
+       
+       for (unsigned int mult=0;mult<nfe.element_multiplicity(base);++mult)
+         {
+           const unsigned int jblock = nfe.first_block_of_base(base) + mult;
+           for (unsigned int i=0;i<fe.dofs_per_cell;++i)
+             if (couple_face(fe.system_to_block_index(i).first, jblock)
+                 != DoFTools::none)
+               {
+                 matrix(i,jblock) += increment;
+               }
+         }
+      }
   
-                                  // The dofs on the common face
-                                  // will be handled below,
-                                  // therefore, we subtract them
-                                  // here.
-  for (unsigned int base=0;base<nfe.n_base_elements();++base)
-    {
-      const unsigned int increment = nfe.base_element(base).dofs_per_cell
-                                    - nfe.base_element(base).dofs_per_face;
-      
-      for (unsigned int mult=0;mult<nfe.element_multiplicity(base);++mult)
-       {
-         const unsigned int jblock = nfe.first_block_of_base(base) + mult;
-         for (unsigned int i=0;i<fe.dofs_per_cell;++i)
-           if (couple_face(fe.system_to_block_index(i).first, jblock)
-               != DoFTools::none)
-             {
-               matrix(i,jblock) += increment;
-             }
-       }
-    }
-  
-  for (unsigned int base=0;base<fe.n_base_elements();++base)
-    {
-      const unsigned int increment = fe.base_element(base).dofs_per_cell
-                                    - fe.base_element(base).dofs_per_face;
-      
-      for (unsigned int mult=0;mult<fe.element_multiplicity(base);++mult)
-       {
-         const unsigned int jblock = fe.first_block_of_base(base) + mult;
-         for (unsigned int i=0;i<nfe.dofs_per_cell;++i)
-           if (couple_face(nfe.system_to_block_index(i).first, jblock)
-               != DoFTools::none)
-             {
-               nmatrix(i,jblock) += increment;
-             }
-       }
-    }
+                                  // Compute the contributions due to
+                                  // numerical fluxes on the neighbor
+                                  // cell
+  if (couple_face.size(0) != 0)
+    for (unsigned int base=0;base<fe.n_base_elements();++base)
+      {
+       const unsigned int increment = fe.base_element(base).dofs_per_cell
+                                      - fe.base_element(base).dofs_per_face;
+       for (unsigned int mult=0;mult<fe.element_multiplicity(base);++mult)
+         {
+           const unsigned int jblock = fe.first_block_of_base(base) + mult;
+           for (unsigned int i=0;i<nfe.dofs_per_cell;++i)
+             if (couple_face(nfe.system_to_block_index(i).first, jblock)
+                 != DoFTools::none)
+               {
+                 nmatrix(i,jblock) += increment;
+               }
+         }
+      }
                                   // At this point, we assume
                                   // that each cell added its
                                   // dofs minus the face to
@@ -723,10 +726,11 @@ DoFTools::compute_row_length_vector(
                                   // couplings from components to
                                   // blocks, so this works for
                                   // nonprimitive elements as well.
-  std::vector<Table<2, Coupling> > couple_cell;
-  std::vector<Table<2, Coupling> > couple_face;
+  std::vector<Table<2, Coupling> > couple_cell(1);
+  std::vector<Table<2, Coupling> > couple_face(1);
   convert_couplings_to_blocks(dofs, couplings, couple_cell);
-  convert_couplings_to_blocks(dofs, flux_couplings, couple_face);
+  if (flux_couplings.size(0) != 0)
+    convert_couplings_to_blocks(dofs, flux_couplings, couple_face);
 
   Table<2, unsigned int> cell_couplings;
   Table<2, unsigned int> neighbor_couplings;
@@ -839,10 +843,11 @@ DoFTools::compute_row_length_vector(
                                   // couplings from components to
                                   // blocks, so this works for
                                   // nonprimitive elements as well.
-  std::vector<Table<2, Coupling> > couple_cell;
-  std::vector<Table<2, Coupling> > couple_face;
+  std::vector<Table<2, Coupling> > couple_cell(1);
+  std::vector<Table<2, Coupling> > couple_face(1);
   convert_couplings_to_blocks(dofs, couplings, couple_cell);
-  convert_couplings_to_blocks(dofs, flux_couplings, couple_face);
+  if (flux_couplings.size(0) != 0)
+    convert_couplings_to_blocks(dofs, flux_couplings, couple_face);
 
   Table<2, unsigned int> cell_couplings;
   Table<2, unsigned int> neighbor_couplings;
@@ -863,10 +868,14 @@ DoFTools::compute_row_length_vector(
              ExcDimensionMismatch(couplings.n_rows(), fe.n_components()));
       Assert (couplings.n_cols()==fe.n_components(),
              ExcDimensionMismatch(couplings.n_cols(), fe.n_components()));
-      Assert (flux_couplings.n_rows()==fe.n_components(),
-             ExcDimensionMismatch(flux_couplings.n_rows(), fe.n_components()));
-      Assert (flux_couplings.n_cols()==fe.n_components(),
-             ExcDimensionMismatch(flux_couplings.n_cols(), fe.n_components()));
+      if (flux_couplings.n_rows() != 0)
+       Assert (flux_couplings.n_rows()==fe.n_components(),
+               ExcDimensionMismatch(flux_couplings.n_rows(),
+                                    fe.n_components()));
+      if (flux_couplings.n_rows() != 0)
+       Assert (flux_couplings.n_cols()==fe.n_components(),
+               ExcDimensionMismatch(flux_couplings.n_cols(),
+                                    fe.n_components()));
       
       cell_couplings.reinit(fe.dofs_per_cell, fe.n_blocks());
       cell_indices.resize(fe.dofs_per_cell);