org.jgrapht.experimental.isomorphism.IsomorphismRelation Maven / Gradle / Ivy
/* ==========================================
* JGraphT : a free Java graph-theory library
* ==========================================
*
* Project Info: http://jgrapht.sourceforge.net/
* Project Creator: Barak Naveh (http://sourceforge.net/users/barak_naveh)
*
* (C) Copyright 2003-2007, by Barak Naveh and Contributors.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*/
/* -----------------
* IsomorphismRelation.java
* -----------------
* (C) Copyright 2005-2007, by Assaf Lehr and Contributors.
*
* Original Author: Assaf Lehr
* Contributor(s): -
*
* $Id: IsomorphismRelation.java 568 2007-09-30 00:12:18Z perfecthash $
*
* Changes
* -------
*/
package org.jgrapht.experimental.isomorphism;
import java.util.*;
import org.jgrapht.*;
import org.jgrapht.graph.*;
/**
* Holds an isomorphism relation for two graphs. It contains a mapping between
* the two graphs.
*
* Usage:
*
*
* - use
getVertexCorrespondence() or
* getEdgeCorrespondence() to get the mapped object in the other graph.
*
*
*
*
It consists of two vertexes array , the i-th vertex in the 1st array is
* the isomorphic eqv. of the i-th in 2nd array. Note that the getters are
* unsafe (they return the array and not a copy of it).
*
* @author Assaf
* @since May 27, 2005
*/
public class IsomorphismRelation
implements GraphMapping
{
//~ Instance fields --------------------------------------------------------
private List vertexList1;
private List vertexList2;
private GraphMapping graphMapping = null;
private Graph graph1;
private Graph graph2;
//~ Constructors -----------------------------------------------------------
/**
*/
public IsomorphismRelation(
List aGraph1vertexArray,
List aGraph2vertexArray,
Graph g1,
Graph g2)
{
this.vertexList1 = aGraph1vertexArray;
this.vertexList2 = aGraph2vertexArray;
this.graph1 = g1;
this.graph2 = g2;
}
//~ Methods ----------------------------------------------------------------
public String toString()
{
StringBuffer sb = new StringBuffer();
sb.append("vertexList1: ").append(
this.vertexList1.toString());
sb.append("\tvertexList2: ").append(
this.vertexList2.toString());
return sb.toString();
}
public V getVertexCorrespondence(V vertex, boolean forward)
{
// lazy initializer for graphMapping
if (graphMapping == null) {
initGraphMapping();
}
return graphMapping.getVertexCorrespondence(vertex, forward);
}
public E getEdgeCorrespondence(E edge, boolean forward)
{
// lazy initializer for graphMapping
if (graphMapping == null) {
initGraphMapping();
}
return graphMapping.getEdgeCorrespondence(edge, forward);
}
/**
* We currently have the vertexes array. From them we will construct two
* maps: g1ToG2 and g2ToG1, using the array elements with the same index.
*/
private void initGraphMapping()
{
int mapSize = vertexList1.size();
Map g1ToG2 = new HashMap(mapSize);
Map g2ToG1 = new HashMap(mapSize);
for (int i = 0; i < mapSize; i++) {
V source = this.vertexList1.get(i);
V target = this.vertexList2.get(i);
g1ToG2.put(source, target);
g2ToG1.put(target, source);
}
this.graphMapping =
new DefaultGraphMapping(
g1ToG2,
g2ToG1,
this.graph1,
this.graph2);
}
}
// End IsomorphismRelation.java