/**
* 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 euclidean distance.
*
* @author Sebastian Land, Ingo Mierswa, Michael Wurst
*/
public class EuclideanDistance extends DistanceMeasure {
private static final long serialVersionUID = -6802412021495569400L;
@Override
public double calculateDistance(double[] value1, double[] value2) {
double sum = 0.0;
int counter = 0;
for (int i = 0; i < value1.length; i++) {
if ((!Double.isNaN(value1[i])) && (!Double.isNaN(value2[i]))) {
double diff = value1[i] - value2[i];
sum += diff * diff;
counter++;
}
}
if (counter > 0) {
return Math.sqrt(sum);
} else {
return Double.NaN;
}
}
@Override
public double calculateSimilarity(double[] value1, double[] value2) {
return -calculateDistance(value1, value2);
}
// doing nothing
@Override
public void init(ExampleSet exampleSet) throws OperatorException {
super.init(exampleSet);
Tools.onlyNumericalAttributes(exampleSet, "value based similarities");
}
@Override
public String toString() {
return "Euclidean distance";
}
}