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 021import org.apache.commons.math3.exception.DimensionMismatchException; 022 023/** 024 * Interface for distance measures of n-dimensional vectors. 025 * 026 * @since 3.2 027 */ 028public interface DistanceMeasure extends Serializable { 029 030 /** 031 * Compute the distance between two n-dimensional vectors. 032 * <p> 033 * The two vectors are required to have the same dimension. 034 * 035 * @param a the first vector 036 * @param b the second vector 037 * @return the distance between the two vectors 038 * @throws DimensionMismatchException if the array lengths differ. 039 */ 040 double compute(double[] a, double[] b) throws DimensionMismatchException; 041}