001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.math3.ml.distance;
018
019import java.io.Serializable;
020
021/**
022 * Interface for distance measures of n-dimensional vectors.
023 *
024 * @since 3.2
025 */
026public interface DistanceMeasure extends Serializable {
027
028    /**
029     * Compute the distance between two n-dimensional vectors.
030     * <p>
031     * The two vectors are required to have the same dimension.
032     *
033     * @param a the first vector
034     * @param b the second vector
035     * @return the distance between the two vectors
036     */
037    double compute(double[] a, double[] b);
038}