/*
* 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.similarity.bregmandivergences;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.Example;
import com.rapidminer.example.ExampleSet;
/**
* The "KL-divergence ".
*
* @author Regina Fritsch
* @version $Id: KLDivergence.java,v 1.4 2008/09/12 10:30:43 tobiasmalbrecht Exp $
*/
public class KLDivergence extends AbstractBregmanDivergence {
public KLDivergence(ExampleSet es) throws InstantiationException {
super(es);
}
public double distance(Example x, double[] y) {
double result = 0;
int i = 0;
for (Attribute attribute : x.getAttributes()) {
result += x.getValue(attribute) * logXToBaseY(x.getValue(attribute)/y[i],2);
i++;
}
return result;
}
public boolean isApplicable(Example x) {
return true;
}
}