diff -r a34203867181 -r 269f0cbfbcc8 lemon/grid_graph.h
--- a/lemon/grid_graph.h	Fri Sep 30 13:13:42 2005 +0000
+++ b/lemon/grid_graph.h	Fri Sep 30 13:15:28 2005 +0000
@@ -27,8 +27,21 @@
 
 #include <lemon/bits/undir_graph_extender.h>
 
+#include <lemon/xy.h>
+
+///\ingroup graphs
+///\file
+///\brief GridGraph class.
+
 namespace lemon {
 
+  /// \brief Base graph for GridGraph.
+  ///
+  /// Base graph for grid graph. It describes some member functions
+  /// which can be used in the GridGraph.
+  ///
+  /// \warning Always use the GridGraph instead of this.
+  /// \see GridGraph
   class GridGraphBase {
 
   public:
@@ -356,9 +369,91 @@
   /// "Undirected Graph" concept.
   ///
   /// \author Balazs Dezso
+  /// \see GridGraphBase
   class GridGraph : public ExtendedGridGraphBase {
   public:
-    
+
+    /// \brief Map to get the indices of the nodes as xy<int>.
+    ///
+    /// Map to get the indices of the nodes as xy<int>.
+    class IndexMap {
+    public:
+      typedef True NeedCopy;
+      /// \brief The key type of the map
+      typedef GridGraph::Node Key;
+      /// \brief The value type of the map
+      typedef xy<int> Value;
+
+      /// \brief Constructor
+      ///
+      /// Constructor
+      IndexMap(const GridGraph& _graph) : graph(_graph) {}
+
+      /// \brief The subscript operator
+      ///
+      /// The subscript operator.
+      Value operator[](Key key) const {
+	return xy<int>(graph.row(key), graph.col(key));
+      }
+
+    private:
+      const GridGraph& graph;
+    };
+
+    /// \brief Map to get the row of the nodes.
+    ///
+    /// Map to get the row of the nodes.
+    class RowMap {
+    public:
+      typedef True NeedCopy;
+      /// \brief The key type of the map
+      typedef GridGraph::Node Key;
+      /// \brief The value type of the map
+      typedef int Value;
+
+      /// \brief Constructor
+      ///
+      /// Constructor
+      RowMap(const GridGraph& _graph) : graph(_graph) {}
+
+      /// \brief The subscript operator
+      ///
+      /// The subscript operator.
+      Value operator[](Key key) const {
+	return graph.row(key);
+      }
+
+    private:
+      const GridGraph& graph;
+    };
+
+    /// \brief Map to get the column of the nodes.
+    ///
+    /// Map to get the column of the nodes.
+    class ColMap {
+    public:
+      typedef True NeedCopy;
+      /// \brief The key type of the map
+      typedef GridGraph::Node Key;
+      /// \brief The value type of the map
+      typedef int Value;
+
+      /// \brief Constructor
+      ///
+      /// Constructor
+      ColMap(const GridGraph& _graph) : graph(_graph) {}
+
+      /// \brief The subscript operator
+      ///
+      /// The subscript operator.
+      Value operator[](Key key) const {
+	return graph.col(key);
+      }
+
+    private:
+      const GridGraph& graph;
+    };
+
     GridGraph(int n, int m) { construct(n, m); }
     
     /// \brief Gives back the edge goes down from the node.
@@ -398,5 +493,26 @@
     }
     
   };
+
+  /// \brief Index map of the grid graph
+  ///
+  /// Just returns an IndexMap for the grid graph.
+  GridGraph::IndexMap indexMap(const GridGraph& graph) {
+    return GridGraph::IndexMap(graph);
+  }
+
+  /// \brief Row map of the grid graph
+  ///
+  /// Just returns an RowMap for the grid graph.
+  GridGraph::RowMap rowMap(const GridGraph& graph) {
+    return GridGraph::RowMap(graph);
+  }
+
+  /// \brief Coloumn map of the grid graph
+  ///
+  /// Just returns an ColMap for the grid graph.
+  GridGraph::ColMap colMap(const GridGraph& graph) {
+    return GridGraph::ColMap(graph);
+  }
 }
 #endif