/*
* 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.tools.math.matrix;
import java.util.List;
import java.util.Random;
import com.rapidminer.tools.IterationArrayList;
import com.rapidminer.tools.RandomGenerator;
/**
* Compare matrices using absolute distance.
*
* @author Michael Wurst
* @version $Id: AbsoluteDistanceMatrixComparator.java,v 1.5 2008/09/12 10:29:52 tobiasmalbrecht Exp $
*
*/
public class AbsoluteDistanceMatrixComparator<Ex, Ey> implements MatrixComparator<Ex, Ey> {
public double compare(Matrix<Ex, Ey> m1, Matrix<Ex, Ey> m2, double samplingRate) {
List<Ex> xLabels = new IterationArrayList<Ex>(m1.getXLabels());
List<Ey> yLabels = new IterationArrayList<Ey>(m1.getYLabels());
int counter = 0;
double dist = 0.0;
Random rng = RandomGenerator.getGlobalRandomGenerator();
for (int i = 0; i < xLabels.size(); i++) {
Ex x = xLabels.get(i);
for (int j = 0; j < yLabels.size(); j++) {
if (rng.nextDouble() < samplingRate) {
Ey y = yLabels.get(j);
double d = Math.abs(m1.getEntry(x, y) - m2.getEntry(x, y));
if (!Double.isInfinite(d) && !Double.isNaN(d)) {
counter++;
dist = dist + d;
}
}
}
}
return dist / counter;
}
public boolean getReciprogalFitness() {
return true;
}
}