]> https://gitweb.dealii.org/ - dealii.git/commitdiff
Doc updates.
authorWolfgang Bangerth <bangerth@math.tamu.edu>
Fri, 22 May 1998 07:38:35 +0000 (07:38 +0000)
committerWolfgang Bangerth <bangerth@math.tamu.edu>
Fri, 22 May 1998 07:38:35 +0000 (07:38 +0000)
git-svn-id: https://svn.dealii.org/trunk@329 0785d39b-7218-0410-832d-ea1e28bc413d

deal.II/deal.II/include/fe/fe.h
deal.II/deal.II/include/numerics/matrices.h
deal.II/deal.II/include/numerics/vectors.h

index 2514f1c50eb68c41d42832ea1106ff76585f710b..6e3fad1ca8edea5fb6df2791c163b1d09b0dda8a 100644 (file)
@@ -408,7 +408,7 @@ struct FiniteElementBase : public FiniteElementData<dim> {
  *   the present library).
  *
  *   Both these assumptions are used when interpolation of a continuous
- *   function to the finite element space is applied. At present, only two
+ *   function to the finite element space is applied. At present, only few
  *   places where this is used in the library come to mind to the author,
  *   namely the treating of boundary values in the #ProblemBase# class and
  *   the interpolation in the #VectorCreator# collection. You should also
@@ -416,6 +416,21 @@ struct FiniteElementBase : public FiniteElementData<dim> {
  *   made if you want to use elements of other classes. A hint may be the
  *   use of the #get_ansatz_points# and #get_face_ansatz_points# functions
  *   of this class.
+ *
+ * \item Vanishing of basis functions on faces: when projecting a function
+ *   to the boundary, use if made of the assumption that all basis functions
+ *   on a cell adjacent to the boundary vanish on the boundary except for those
+ *   on the boundary face itself. For Lagrange elements this is true, but it
+ *   may or may not be true in other cases.
+ *
+ *   This assumption is used in the #VectorTools::project_boundary_values#,
+ *   #MatrixCreator::create_boundary_mass_matrix#,
+ *   #DoFHandler::make_boundary_sparsity_pattern#,
+ *   #DoFHandler::map_dof_to_boundary_indices# and may be a few other places.
+ *   The places in the #DoFHandler# class are probably not that dangerous,
+ *   since wrong results will most likely lead to internal errors through
+ *   the #Assert# mechanism, but the first places will lead to undiscovered
+ *   errors if not thought of properly.
  * \end{itemize}
  *
  * @author Wolfgang Bangerth, 1998
index c61dccc1508bc5c0baa708ba7e011bc52f76b24a..692df0603b3e7ed5510903155ee707bc4dd35739 100644 (file)
@@ -8,7 +8,6 @@
 
 #include <base/exceptions.h>
 #include <map>
-#include <set>
 
 template <int dim> class Triangulation;
 template <int dim> class DoFHandler;
@@ -231,6 +230,15 @@ class MatrixCreator {
                                       const Function<dim>      &rhs,
                                       dVector                  &rhs_vector,
                                       const Function<dim>      *a = 0);
+
+                                    /**
+                                     * Exception
+                                     */
+    DeclException0 (ExcNotImplemented);
+                                    /**
+                                     * Exception
+                                     */
+    DeclException0 (ExcInternalError);
 };
 
 
@@ -318,11 +326,6 @@ class MatrixTools : public MatrixCreator<dim> {
                                       dSMatrix              &matrix,
                                       dVector               &solution,
                                       dVector               &right_hand_side);
-
-                                    /**
-                                     * Exception
-                                     */
-    DeclException0 (ExcNotImplemented);
 };
 
 
index c5a7ff36dbd42a0ec3a67ca5408eb181474c8460..81c4812ae6321fc0499877e115029da64cc0a714 100644 (file)
@@ -121,7 +121,7 @@ enum NormType {
  *   Within this function, boundary values are interpolated, i.e. a node is given
  *   the point value of the boundary function. In some cases, it may be necessary
  *   to use the L2-projection of the boundary function or any other method. For
- *   this purpose other functions refer to the #VectorTools::project_boundary_values#
+ *   this purpose to the #VectorTools::project_boundary_values#
  *   function below.
  *
  *   You should be aware that the boundary function may be evaluated at nodes
@@ -259,7 +259,12 @@ class VectorTools {
                                      * to Dirichlet boundary conditions
                                      * and the values they are to be
                                      * assigned, by interpolation around
-                                     * the boundary.
+                                     * the boundary. If the
+                                     * #boundary_values# contained values
+                                     * before, the new ones are added, or
+                                     * the old one overwritten if a node
+                                     * of the boundary part to be prjected
+                                     * on already was in the variable.
                                      *
                                      * See the general doc for more
                                      * information.
@@ -273,7 +278,12 @@ class VectorTools {
                                     /**
                                      * Project #function# to the boundary
                                      * of the domain, using the given quadrature
-                                     * formula for the faces.
+                                     * formula for the faces. If the
+                                     * #boundary_values# contained values
+                                     * before, the new ones are added, or
+                                     * the old one overwritten if a node
+                                     * of the boundary part to be prjected
+                                     * on already was in the variable.
                                      *
                                      * See the general documentation of this
                                      * class for further information.

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