/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.mahout.common.distance;
import org.apache.mahout.math.Vector;
/**
* This class implements a Euclidean distance metric by summing the square root of the squared differences
* between each coordinate.
* <p/>
* If you don't care about the true distance and only need the values for comparison, then the base class,
* {@link SquaredEuclideanDistanceMeasure}, will be faster since it doesn't do the actual square root of the
* squared differences.
*/
public class EuclideanDistanceMeasure extends SquaredEuclideanDistanceMeasure {
@Override
public double distance(Vector v1, Vector v2) {
return Math.sqrt(super.distance(v1, v2));
}
@Override
public double distance(double centroidLengthSquare, Vector centroid, Vector v) {
return Math.sqrt(super.distance(centroidLengthSquare, centroid, v));
}
}