]> https://gitweb.dealii.org/ - dealii-svn.git/commitdiff
doc update for #get_local_mass_matrix#
authorhartmann <hartmann@0785d39b-7218-0410-832d-ea1e28bc413d>
Wed, 30 Jun 1999 12:56:05 +0000 (12:56 +0000)
committerhartmann <hartmann@0785d39b-7218-0410-832d-ea1e28bc413d>
Wed, 30 Jun 1999 12:56:05 +0000 (12:56 +0000)
git-svn-id: https://svn.dealii.org/trunk@1513 0785d39b-7218-0410-832d-ea1e28bc413d

deal.II/deal.II/include/fe/fe_system.h

index 180f711881175ccf40bd95127b5fac6519d79e97..fff981229cc6f2b39fa647adb95ac479e4eb7de8 100644 (file)
@@ -68,8 +68,7 @@
  * @author Wolfgang Bangerth, Guido Kanschat, 1999
  */
 template <int dim>
-class FESystem //<dim>
-  : public FiniteElement<dim>
+class FESystem : public FiniteElement<dim>
 {
                                     /**
                                      * Copy constructor prohibited.
@@ -201,17 +200,17 @@ class FESystem //<dim>
                                      * cell $K$. However, here only those
                                      * elements of the matrix are set for which
                                      * the shape functions $\phi_i$ and
-                                     * $\phi_j$ belong to the same subelement,
+                                     * $\phi_j$ belong to the same component,
                                      * i.e. the resulting matrix is a block
-                                     * matrix where each block is a diagonal
-                                     * matrix with diagonal values equal to
+                                     * diagonal matrix where each block is a
+                                     * matrix with values equal to
                                      * the respective entry of the local mass
                                      * matrix for the underlying finite element
                                      * class. This definition of the mass
                                      * matrix for systems of finite elements
                                      * is consistent with the use of the matrix
                                      * for the projection of initial values and
-                                     * the like, where the subelements are not
+                                     * the like, where the components are not
                                      * coupled to each other. Also in most
                                      * other cases you will not want the
                                      * coupling terms to appear in the mass
@@ -220,12 +219,20 @@ class FESystem //<dim>
                                      * If the shape functions of this element
                                      * were numbered such that the first
                                      * numbers are for the shape functions of
-                                     * the first subelement, then those for
-                                     * the second subelement, and so on, then
+                                     * the first component, then those for
+                                     * the second component, and so on, then
                                      * the mass matrix generated by this
                                      * function would be a block diagonal
                                      * matrix with each block being the mass
-                                     * matrix of the base finite element.
+                                     * matrix of the base finite element as
+                                     * described above. However, this is
+                                     * not the numbering used by the
+                                     * #FESystem# class, so the block
+                                     * structure is usually lost for
+                                     * the {\it local} mass matrices, but
+                                     * can be recovered in the global
+                                     * matrix by suitable renumbering
+                                     * of global DoF numbers.
                                      *
                                      * Refer to the base class for more
                                      * information on this function.

In the beginning the Universe was created. This has made a lot of people very angry and has been widely regarded as a bad move.

Douglas Adams


Typeset in Trocchi and Trocchi Bold Sans Serif.