src/main/java/org/apache/commons/math3/ml/distance/DistanceMeasure.java

/*
 * 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.commons.math3.ml.distance;

import java.io.Serializable;

import org.apache.commons.math3.exception.DimensionMismatchException;

/**
 * Interface for distance measures of n-dimensional vectors.
 *
 * @since 3.2
 */
public interface DistanceMeasure extends Serializable {

    /**
     * Compute the distance between two n-dimensional vectors.
     * <p>
     * The two vectors are required to have the same dimension.
     *
     * @param a the first vector
     * @param b the second vector
     * @return the distance between the two vectors
     * @throws DimensionMismatchException if the array lengths differ.
     */
    double compute(double[] a, double[] b) throws DimensionMismatchException;
}