/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.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.similarity.numerical;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.Tools;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.tools.math.similarity.DistanceMeasure;
/**
* The Camberra distance measure.
*
* @author Sebastian Land, Michael Wurst
*/
public class CamberraNumericalDistance extends DistanceMeasure {
private static final long serialVersionUID = 1787035984412649082L;
@Override
public double calculateDistance(double[] value1, double[] value2) {
double sum = 0.0;
boolean changed = false;
for (int i = 0; i < value1.length; i++) {
double v1 = value1[i];
double v2 = value2[i];
if ((!Double.isNaN(v1)) && (!Double.isNaN(v2))) {
sum = sum + Math.abs(v1 - v2) / Math.abs(v1 + v2);
changed = true;
}
}
return changed ? sum : Double.NaN;
}
@Override
public double calculateSimilarity(double[] value1, double[] value2) {
return -calculateDistance(value1, value2);
}
@Override
public void init(ExampleSet exampleSet) throws OperatorException {
super.init(exampleSet);
Tools.onlyNumericalAttributes(exampleSet, "value based similarities");
}
@Override
public String toString() {
return "Camberra numerical distance";
}
}