Make the documentation of one function slightly clearer.

git-svn-id: https://svn.dealii.org/trunk@32656 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/include/deal.II/numerics/vector_tools.h b/deal.II/include/deal.II/numerics/vector_tools.h
index 9558de7a4283858e904b4c0936310b48cb655647..b1570b6c67ab2bed57bffe748b43da83b4b9fbab 100644 (file)
--- a/deal.II/include/deal.II/numerics/vector_tools.h
+++ b/deal.II/include/deal.II/numerics/vector_tools.h
@@ -1,7 +1,7 @@
 // ---------------------------------------------------------------------
 // $Id$
 //
-// Copyright (C) 1998 - 2013 by the deal.II authors
+// Copyright (C) 1998 - 2014 by the deal.II authors
 //
 // This file is part of the deal.II library.
 //
@@ -1675,8 +1675,11 @@ namespace VectorTools
 
   /**
    * Compute the constraints that correspond to boundary conditions of the
-   * form $\vec n \times \vec u=0$, i.e. flow normal to the boundary if $\vec
-   * u$ is a vector-valued quantity. This function constrains exactly those
+   * form $\vec n \times \vec u=0$. This corresponds to flow with no tangential
+   * component, i.e. flow is parallel to the normal vector to the boundary if $\vec
+   * u$ is a vector-valued quantity.
+   *
+   * This function constrains exactly those
    * vector-valued components that are left unconstrained by
    * compute_no_normal_flux_constraints, and leaves the one component
    * unconstrained that is constrained by compute_no_normal_flux_constraints.