From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Wed, 6 Apr 2005 13:09:05 +0000 (+0000)
Subject: Clarify docs.
X-Git-Tag: v8.0.0~14165
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=482fd7d566f366c25d484b6d55d2cfabc5371f80;p=dealii.git

Clarify docs.


git-svn-id: https://svn.dealii.org/trunk@10382 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/base/include/base/symmetric_tensor.h b/deal.II/base/include/base/symmetric_tensor.h
index 9e2ff62c30..5fe4c4cd27 100644
--- a/deal.II/base/include/base/symmetric_tensor.h
+++ b/deal.II/base/include/base/symmetric_tensor.h
@@ -695,7 +695,8 @@ class SymmetricTensor
 				      * of rank 2. For example, if the
 				      * present object is also a
 				      * rank-2 tensor, then this is
-				      * the scalar-product contraction
+				      * the scalar-product double
+				      * contraction
 				      * <tt>a<sub>ij</sub>b<sub>ij</sub></tt>
 				      * over all indices
 				      * <tt>i,j</tt>. In this case,
@@ -715,6 +716,20 @@ class SymmetricTensor
 				      * present object and the indices
 				      * of the argument, and the
 				      * result is a tensor of rank 2.
+				      *
+				      * Note that the multiplication
+				      * operator for symmetrict
+				      * tensors is defined to be a
+				      * double contraction over two
+				      * indices, while it is defined
+				      * as a single contraction over
+				      * only one index for regular
+				      * <tt>Tensor</tt> objects. For
+				      * symmetric tensors it therefore
+				      * acts in a way that is commonly
+				      * denoted by a "colon
+				      * multiplication" in the
+				      * mathematica literature.
                                       */
     typename internal::SymmetricTensorAccessors::double_contraction_result<rank,2,dim>::type
     operator * (const SymmetricTensor<2,dim> &s) const;