GRAPHCENTER Center of a graph.

   CENTER = graphCenter(V, E)
   Computes the center of the graph given by V and E. The center of the
   graph is the set of vertices whose eccentricity is minimal. The
   function returns indices of center vertices.

   CENTER = graphCenter(V, E, L)
   Specifies the weight of each edge for computing the distances. Default
   is to consider a weight of 1 for each edge.

   Example
     nodes = [20 20;20 50;20 80;50 50;80 20;80 50;80 80];
     edges = [1 2;2 3;2 4;4 6;5 6;6 7];
     figure; drawGraph(nodes, edges);
     axis([0 100 0 100]); axis equal; hold on
     C = graphCenter(nodes, edges)
     C = 
         4  

   See Also
   grPropagateDistance, grVertexEccentricity
   graphRadius, graphDiameter, graphPeripheralVertices


 ------
 Author: David Legland
 e-mail: david.legland@grignon.inra.fr
 Created: 2010-09-07,    using Matlab 7.9.0.529 (R2009b)
 Copyright 2010 INRA - Cepia Software Platform.

Package: matgeom