Exception for missing prolongation matrices

git-svn-id: https://svn.dealii.org/trunk@5668 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/deal.II/include/multigrid/mg_transfer.h b/deal.II/deal.II/include/multigrid/mg_transfer.h
index 527d04b8a72c435023286565efd53930a5b18ad9..f76a4e8d65268fafd8f4fe0352ce6b2ccf431444 100644 (file)
--- a/deal.II/deal.II/include/multigrid/mg_transfer.h
+++ b/deal.II/deal.II/include/multigrid/mg_transfer.h
@@ -136,6 +136,12 @@ class MGTransferPrebuilt : public Subscriptor // MGTransferBase<Vector<double> >
                      OutVector &dst,
                      const MGLevelObject<Vector<double> > &src) const;
 
+                                    /**
+                                     * Finite element does not
+                                     * provide prolongation matrices.
+                                     */
+    DeclException0(ExcNoProlongation);
+    
   private:
 
                                   /**

diff --git a/deal.II/deal.II/source/multigrid/multigrid.cc b/deal.II/deal.II/source/multigrid/multigrid.cc
index cc65bc9e1c41532f71bffdf6fc8620d9e587223f..f7781ad8706a07108fafb1be0f73b175999d68ae 100644 (file)
--- a/deal.II/deal.II/source/multigrid/multigrid.cc
+++ b/deal.II/deal.II/source/multigrid/multigrid.cc
@@ -83,7 +83,9 @@ void MGTransferPrebuilt::build_matrices (const MGDoFHandler<dim> &mg_dof)
                                                 // this child
                const FullMatrix<double> &prolongation
                  = mg_dof.get_fe().prolongate(child);
-           
+
+               Assert (prolongation.n() != 0, ExcNoProlongation());
+               
                cell->child(child)->get_mg_dof_indices (dof_indices_child);
 
                                                 // now tag the entries in the