Update documentation of TriaAccessor::barycenter.

diff --git a/include/deal.II/grid/tria_accessor.h b/include/deal.II/grid/tria_accessor.h
index 37798404f699d1d0151704f1791929c4c128ee24..22ac5d147b3d4cff03e91cb876715373a43359da 100644 (file)
--- a/include/deal.II/grid/tria_accessor.h
+++ b/include/deal.II/grid/tria_accessor.h
@@ -1290,7 +1290,21 @@ public:
                           const bool use_laplace_transformation=false) const;
 
   /**
-   * Barycenter of the object.
+   * Return the barycenter (also called centroid)
+   * of the object. The barycenter for an object $K$
+   * of dimension $d$ in $D$ space dimensions is given by the $D$-dimensional
+   * vector $\mathbf x_K$ defined by
+   * @f{
+   *   \mathbf x_K = \frac{1}{|K|} \int_K \mathbf x \; \textrm{d}x
+   * @f}
+   * where the measure of the object is given by
+   * @f{
+   *   |K| = \int_K \mathbf 1 \; \textrm{d}x.
+   * @f}
+   * This function assumes that $K$ is mapped by a $d$-linear function from
+   * the reference $d$-dimensional cell. Then the integrals above can be
+   * pulled back to the reference cell and evaluated exactly (if through
+   * lengthy and, compared to the center() function, expensive computations).
    */
   Point<spacedim> barycenter () const;
 

diff --git a/source/grid/tria_accessor.cc b/source/grid/tria_accessor.cc
index a043d573f55d0c29ed6b4b2ddaa324fb5cb0d024..73a767f36c7692d7b4a237c97625f2b94819527f 100644 (file)
--- a/source/grid/tria_accessor.cc
+++ b/source/grid/tria_accessor.cc
@@ -141,7 +141,7 @@ namespace
     /*
       Get the computation of the barycenter by this little Maple script. We
       use the bilinear mapping of the unit quad to the real quad. However,
-      every transformation mapping the unit faces to strait lines should
+      every transformation mapping the unit faces to straight lines should
       do.
 
       Remember that the area of the quad is given by