Augment a comment.

git-svn-id: https://svn.dealii.org/trunk@18540 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/deal.II/include/fe/fe_values.h b/deal.II/deal.II/include/fe/fe_values.h
index 15f181af60eef0edc0b4a325acfaf051cba08232..5efbd524025a18d59098d3f502b5858a4a4d4d69 100644 (file)
--- a/deal.II/deal.II/include/fe/fe_values.h
+++ b/deal.II/deal.II/include/fe/fe_values.h
@@ -2153,10 +2153,16 @@ class FEValuesBase : protected FEValuesData<dim,spacedim>,
                                      *
                                      * For surface evaluations
                                      * (i.e. classes FEFaceValues or
-                                     * FESubfaceValues), is the
+                                     * FESubfaceValues), it is the
                                      * mapped surface element times
                                      * the weight of the quadrature
                                      * point.
+                                     *
+                                     * You can think of the quantity returned
+                                     * by this function as the volume or
+                                     * surface element $dx, ds$ in the
+                                     * integral that we implement here by
+                                     * quadrature.
                                      */
     double JxW (const unsigned int quadrature_point) const;