From: Martin Kronbichler Date: Fri, 17 Apr 2009 09:50:45 +0000 (+0000) Subject: Update comments about inhomogeneous constraints. X-Git-Tag: v8.0.0~7830 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7a9324015d8c8a842de54ff31fee49a47683045b;p=dealii.git Update comments about inhomogeneous constraints. git-svn-id: https://svn.dealii.org/trunk@18640 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/lac/include/lac/constraint_matrix.h b/deal.II/lac/include/lac/constraint_matrix.h index 807d581ed2..bd34947289 100644 --- a/deal.II/lac/include/lac/constraint_matrix.h +++ b/deal.II/lac/include/lac/constraint_matrix.h @@ -60,17 +60,13 @@ class BlockIndices; * * @image html hp-refinement-simple.png * - * there are three constraints: first $x_2=\frac 12 x_0 + \frac 12 - * x_1$, then $x_4=\frac 14 x_0 + \frac 34 x_1$, and finally the - * identity $x_3=x_1$. All three constraints fit the form given - * above. Similar constraints occur as hanging nodes even if all used - * finite elements are identical. While they are most frequent for - * hanging nodes, constraints of the given form appear also in other - * contexts, see for example the application the @ref step_11 - * "step-11" tutorial program. A special case also covered by the - * current class is the constraint $x_i=0$ although this constraint on - * linear systems is better and more efficiently handled by the - * MatrixTools::apply_boundary_values function. + * there are three constraints: first $x_2=\frac 12 x_0 + \frac 12 x_1$, + * then $x_4=\frac 14 x_0 + \frac 34 x_1$, and finally the identity + * $x_3=x_1$. All three constraints fit the form given above. Similar + * constraints occur as hanging nodes even if all used finite elements are + * identical. While they are most frequent for hanging nodes, constraints of + * the given form appear also in other contexts, see for example the + * application the @ref step_11 "step-11" tutorial program. * * The algorithms used in the implementation of this class are described in * some detail in the @ref hp_paper "hp paper". @@ -78,12 +74,12 @@ class BlockIndices; * *

Using the ConstraintMatrix for Dirichlet boundary conditions

* - * The ConstraintMatrix provides an alternative to implementing Dirichlet - * boundary conditions (where the alternative is to use the functions - * VectorTools::interpolate_boundary_values and + * The ConstraintMatrix provides an alternative for implementinging + * Dirichlet boundary conditions (the standard way that is extensively + * discussed in the tutorial programs is to use * MatrixTools::apply_boundary_values). The general principle of Dirichlet * conditions are algebraic constraints of the form $x_{i} = b_i$, which - * fits into the form as described above. + * fits into the form described above. * * *

Description of constraints