/* Copyright (C) 2003 Univ. of Massachusetts Amherst, Computer Science Dept.
This file is part of "MALLET" (MAchine Learning for LanguagE Toolkit).
http://www.cs.umass.edu/~mccallum/mallet
This software is provided under the terms of the Common Public License,
version 1.0, as published by http://www.opensource.org. For further
information, see the file `LICENSE' included with this distribution. */
package cc.mallet.grmm.inference.gbp;
import java.util.Iterator;
import cc.mallet.grmm.types.Factor;
import cc.mallet.grmm.types.FactorGraph;
import cc.mallet.grmm.types.Variable;
/**
* Created: May 30, 2005
*
* @author <A HREF="mailto:casutton@cs.umass.edu>casutton@cs.umass.edu</A>
* @version $Id: BPRegionGenerator.java,v 1.1 2007/10/22 21:37:58 mccallum Exp $
*/
public class BPRegionGenerator implements RegionGraphGenerator {
public RegionGraph constructRegionGraph (FactorGraph mdl)
{
RegionGraph rg = new RegionGraph ();
for (Iterator it = mdl.factorsIterator (); it.hasNext();) {
Factor ptl = (Factor) it.next ();
if (ptl.varSet ().size() == 1) continue; // Single-node potentials handled separately
Region parent = new Region (ptl);
// Now add appropriate edges to region graph
for (Iterator childIt = ptl.varSet().iterator (); childIt.hasNext();) {
Variable var = (Variable) childIt.next ();
Factor childPtl = mdl.factorOf (var);
Region child = rg.findRegion (childPtl, true);
//add node potential to parent if necessary
if (childPtl != null) {
parent.addFactor (childPtl);
child.addFactor (childPtl);
}
rg.add (parent, child);
}
}
rg.computeInferenceCaches ();
return rg;
}
}