]> https://gitweb.dealii.org/ - dealii.git/commitdiff
Add some documentation (for a frequently asked question)
authorWolfgang Bangerth <bangerth@math.tamu.edu>
Tue, 20 Jan 2004 16:13:29 +0000 (16:13 +0000)
committerWolfgang Bangerth <bangerth@math.tamu.edu>
Tue, 20 Jan 2004 16:13:29 +0000 (16:13 +0000)
git-svn-id: https://svn.dealii.org/trunk@8330 0785d39b-7218-0410-832d-ea1e28bc413d

deal.II/deal.II/include/dofs/dof_constraints.h
deal.II/deal.II/include/grid/tria_accessor.h

index 533792574fa7ca5999cdd482fa7f8793e2e89fb3..de2929f3fd0fde9e9e84162719fc0cdd34a15afc 100644 (file)
@@ -2,7 +2,7 @@
 //    $Id$
 //    Version: $Name$
 //
-//    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 by the deal.II authors
+//    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004 by the deal.II authors
 //
 //    This file is subject to QPL and may not be  distributed
 //    without copyright and license information. Please refer
@@ -106,13 +106,17 @@ class BlockIndices;
  * arguments refer to the first possibility above, those taking only one do
  * their job in-place and refer to the second possibility.
  *
- * Condensing vectors works exactly as described above for matrices.
+ * Condensing vectors works exactly as described above for matrices. Note that
+ * condensation is an idempotent operation, i.e. doing it more than once on a
+ * vector or matrix yields the same result as doing it only once: once an
+ * object has been condensed, further condensation operations don't change it
+ * any more.
  *
  * After solving the condensed system of equations, the solution vector has to
- * be redistributed. This is done by the two @p{distribute} function, one working
- * with two vectors, one working in-place. The operation of distribution undoes
- * the condensation process in some sense, but it should be noted that it is not
- * the inverse operation.
+ * be redistributed. This is done by the two @p{distribute} function, one
+ * working with two vectors, one working in-place. The operation of
+ * distribution undoes the condensation process in some sense, but it should
+ * be noted that it is not the inverse operation.
  *
  * @author Wolfgang Bangerth, 1998
  */
index 664687eab90bc8dedf4056683e527207dc4142af..331b63ed065769924b4d2a6c939702221dfda527 100644 (file)
@@ -2,7 +2,7 @@
 //    $Id$
 //    Version: $Name$
 //
-//    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 by the deal.II authors
+//    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004 by the deal.II authors
 //
 //    This file is subject to QPL and may not be  distributed
 //    without copyright and license information. Please refer
@@ -324,6 +324,14 @@ class TriaObjectAccessor :  public TriaAccessor<dim>
                                      *  down in the documentation of
                                      *  the @ref{Triangulation}
                                      *  class.
+                                     *
+                                     *  Note that the returned value is only
+                                     *  the index of the geometrical
+                                     *  vertex. It has nothing to do with
+                                     *  possible degrees of freedom
+                                     *  associated with it. For this, see the
+                                     *  @p{DoFAccessor::vertex_dof_index}
+                                     *  functions.
                                      */ 
     int vertex_index (const unsigned int i) const;
 
@@ -819,6 +827,14 @@ class TriaObjectAccessor<1, dim> :  public TriaAccessor<dim>
                                     /**
                                      *  Return the index of vertex
                                      *  @p{i=0,1} of a line.
+                                     *
+                                     *  Note that the returned value is only
+                                     *  the index of the geometrical
+                                     *  vertex. It has nothing to do with
+                                     *  possible degrees of freedom
+                                     *  associated with it. For this, see the
+                                     *  @p{DoFAccessor::vertex_dof_index}
+                                     *  functions.
                                      */ 
     int vertex_index (const unsigned int i) const;
 
@@ -1257,6 +1273,14 @@ class TriaObjectAccessor<2, dim> :  public TriaAccessor<dim>
                                      *  @p{(i+3)%4}. See also the
                                      *  introduced convention
                                      *  (@ref{Triangulation}).
+                                     *
+                                     *  Note that the returned value is only
+                                     *  the index of the geometrical
+                                     *  vertex. It has nothing to do with
+                                     *  possible degrees of freedom
+                                     *  associated with it. For this, see the
+                                     *  @p{DoFAccessor::vertex_dof_index}
+                                     *  functions.
                                      */ 
     int vertex_index (const unsigned int i) const;
 
@@ -1745,6 +1769,14 @@ class TriaObjectAccessor<3, dim> :  public TriaAccessor<dim>
                                      *  down in the documentation of
                                      *  the @ref{Triangulation}
                                      *  class.
+                                     *
+                                     *  Note that the returned value is only
+                                     *  the index of the geometrical
+                                     *  vertex. It has nothing to do with
+                                     *  possible degrees of freedom
+                                     *  associated with it. For this, see the
+                                     *  @p{DoFAccessor::vertex_dof_index}
+                                     *  functions.
                                      */ 
     int vertex_index (const unsigned int i) const;
 

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