1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.math4.legacy.ml.distance;
18
19 /**
20 * Interface for distance measures of n-dimensional vectors.
21 *
22 * @since 3.2
23 */
24 public interface DistanceMeasure {
25
26 /**
27 * Compute the distance between two n-dimensional vectors.
28 * <p>
29 * The two vectors are required to have the same dimension.
30 *
31 * @param a the first vector
32 * @param b the second vector
33 * @return the distance between the two vectors
34 * @throws org.apache.commons.math4.legacy.exception.DimensionMismatchException
35 * if the array lengths differ.
36 */
37 double compute(double[] a, double[] b);
38 }