Clarify documentation.

diff --git a/include/deal.II/lac/constraint_matrix.h b/include/deal.II/lac/constraint_matrix.h
index 64de8f3d6c02e7668a8c14ee89859d373466672e..0f65eb79b3da5f58db92d7e1525f75ae7382de26 100644 (file)
--- a/include/deal.II/lac/constraint_matrix.h
+++ b/include/deal.II/lac/constraint_matrix.h
@@ -991,13 +991,17 @@ public:
    */
 
   /**
-   * Re-distribute the elements of the vector in-place. The @p VectorType may
-   * be a Vector<float>, Vector<double>, BlockVector<tt><...></tt>, a PETSc or
-   * Trilinos vector wrapper class, or any other type having the same
-   * interface.
-   *
-   * @note If called with a TrilinosWrappers::MPI::Vector or
-   * PETScWrappers::MPI::Vector @p vec must not contain ghost elements.
+   * Given a vector, set all constrained degrees of freedom to values
+   * so that the constraints are satisfied. For example, if the
+   * current object stores the constraint $x_3=\frac 12 x_1 + \frac 12
+   * x_2$, then this function will read the values of $x_1$ and $x_1$
+   * from the given vector and set the element $x_3$ according to this
+   * constraints. Similarly, if the current object stores the
+   * constraint $x_42=208$, then this function will set the 42nd
+   * element of the given vector to 208.
+   *
+   * @note If this function is called with a parallel vector @p vec,
+   * then the vector must not contain ghost elements.
    */
   template <class VectorType>
   void distribute (VectorType &vec) const;