From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Mon, 24 Jul 2000 07:46:31 +0000 (+0000)
Subject: Add hint to library class.
X-Git-Tag: v8.0.0~20232
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b881bf53ca1ba32605d9e5793bd56761d10c6a71;p=dealii.git

Add hint to library class.


git-svn-id: https://svn.dealii.org/trunk@3194 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/examples/step-9/step-9.cc b/deal.II/examples/step-9/step-9.cc
index 5ef997513a..dc169920c8 100644
--- a/deal.II/examples/step-9/step-9.cc
+++ b/deal.II/examples/step-9/step-9.cc
@@ -493,7 +493,17 @@ BoundaryValues<dim>::value_list (const vector<Point<dim> > &points,
 				 // approximation of the gradient on
 				 // each cell and weighs that with a
 				 // power of the mesh size, as
-				 // described in the introduction. The
+				 // described in the introduction.
+				 // This class is a simple version of
+				 // the ``DerivativeApproximation''
+				 // class in the library, that uses
+				 // similar techniques to obtain
+				 // finite difference approximations
+				 // of the gradient of a finite
+				 // element field, or if higher
+				 // derivatives.
+				 //
+				 // The
 				 // class has one public static
 				 // function ``estimate'' that is
 				 // called to compute a vector of