/*
* RapidMiner
*
* Copyright (C) 2001-2008 by Rapid-I and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapid-i.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.learner.clustering;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Adds an buttom up index to hierarchical cluster models.
*
* @author Michael Wurst, Ingo Mierswa
* @version $Id: ClusterModelPredecessorIndex.java,v 1.6 2008/09/12 10:30:29 tobiasmalbrecht Exp $
*/
public class ClusterModelPredecessorIndex implements Serializable{
private static final long serialVersionUID = 6899534322386857535L;
private final Map<ClusterNode, ClusterNode> predIndex;
public ClusterModelPredecessorIndex(HierarchicalClusterModel hcm) {
super();
predIndex = new HashMap<ClusterNode, ClusterNode>();
addIndexRec(hcm.getRootNode(), predIndex);
}
private void addIndexRec(ClusterNode node, Map<ClusterNode, ClusterNode> index) {
Iterator<ClusterNode> it = node.getSubNodes();
while (it.hasNext()) {
ClusterNode cn = it.next();
index.put(cn, node);
addIndexRec(cn, index);
}
}
public List<ClusterNode> getPathToRoot(ClusterNode cn) {
List<ClusterNode> result = new ArrayList<ClusterNode>();
ClusterNode node = cn;
while (node != null) {
result.add(node);
node = getPredecessor(node);
}
return result;
}
public ClusterNode getPredecessor(ClusterNode cn) {
return predIndex.get(cn);
}
public ClusterNode getMostSpecificCommonNode(ClusterNode cn1, ClusterNode cn2) {
List<ClusterNode> rpath1 = getPathToRoot(cn1);
List<ClusterNode> rpath2 = getPathToRoot(cn2);
Set path1set = new HashSet<ClusterNode>(rpath1);
Iterator<ClusterNode> it = rpath2.iterator();
ClusterNode node = it.next();
while ((it.hasNext()) && (!path1set.contains(node)))
node = it.next();
return node;
}
}