//---------------------------------------------------------------------------
// $Id$
//
-// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 by the deal.II authors
+// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 by the deal.II authors
//
// This file is subject to QPL and may not be distributed
// without copyright and license information. Please refer
int level () const;
/**
- * Return the index of the
- * element presently pointed to
- * on the present level.
- *
- * Note that these indices are not
- * globally unique for cells (though they
- * may be for faces or edges). Rather, a
- * cell is identified by its refinement
- * level and index within this refinement
- * level, the latter piece of information
- * being what this function
- * returns. Consequently, there may be
- * multiple cells on different refinement
- * levels but with the same index within
- * their level.
- *
- * Similarly, the index returned by this
- * function is not a contiguous set of
- * numbers of each level: going from cell
- * to cell, some of the indices in a
- * level may be unused.
+ * Return the index of the
+ * element presently pointed to
+ * on the present level.
+ *
+ * Within a Triangulation object cells are uniquely identified by a
+ * pair <code>(level, index)</code> where the former is the cell's
+ * refinement level and the latter is the index of the cell within
+ * this refinement level (the latter being what this function
+ * returns). Consequently, there may be multiple cells on different
+ * refinement levels but with the same index within their level.
+ * Contrary to this, if the current object corresponds to a face or
+ * edge, then the object is uniquely identified solely by its index
+ * as faces and edges do not have a refinement level.
+ *
+ * @note The indices objects returned by this function are not a
+ * contiguous set of numbers on each level: going from cell to cell,
+ * some of the indices in a level may be unused.
+ *
+ * @note If the triangulation is actually of type
+ * parallel::distributed::Triangulation then the indices are
+ * relatively only to that part of the distributed triangulation
+ * that is stored on the current processor. In other words, cells
+ * living in the partitions of the triangulation stored on different
+ * processors may have the same index even if they refer to the same
+ * cell, and the may have different indices even if they do refer to
+ * the same cell (e.g., if a cell is owned by one processor but is a
+ * ghost cell on another).
*/
int index () const;