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 import org.junit.Assert;
20 import org.junit.Test;
21
22 /**
23 * Tests for {@link EarthMoversDistance} class.
24 */
25 public class EarthMoversDistanceTest {
26
27 private final DistanceMeasure distance = new EarthMoversDistance();
28 private final double[] a = { 0.1, 0.3, 0.2, 0.0, 0.25, 0.15 };
29 private final double[] b = { 0.3, 0.0, 0.4, 0.1, 0.0, 0.2 };
30
31 @Test
32 public void testZero() {
33 Assert.assertEquals(0, distance.compute(a, a), 0d);
34 }
35
36 @Test
37 public void testZero2() {
38 final double[] zero = new double[] { 0, 0 };
39 Assert.assertEquals(0, distance.compute(zero, zero), 0d);
40 }
41
42 @Test
43 public void test() {
44 double expected = 0.65; //0.2 + 0.1 + 0.1 + 0.2 + 0.05 + 0.0;
45 Assert.assertEquals(expected, distance.compute(a, b), 1e-10);
46 Assert.assertEquals(expected, distance.compute(b, a), 1e-10);
47 }
48 }