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 * https://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
18 /*
19 * This is not the original file distributed by the Apache Software Foundation
20 * It has been modified by the Hipparchus project
21 */
22 package org.hipparchus.clustering.distance;
23
24 import org.junit.jupiter.api.Test;
25
26 import static org.junit.jupiter.api.Assertions.assertEquals;
27
28 /**
29 * Tests for {@link EarthMoversDistance} class.
30 */
31 class EarthMoversDistanceTest {
32
33 final DistanceMeasure distance = new EarthMoversDistance();
34 final double[] a = { 0.1, 0.3, 0.2, 0.0, 0.25, 0.15 };
35 final double[] b = { 0.3, 0.0, 0.4, 0.1, 0.0, 0.2 };
36
37 @Test
38 void testZero() {
39 assertEquals(0, distance.compute(a, a), 0d);
40 }
41
42 @Test
43 void testZero2() {
44 final double[] zero = new double[] { 0, 0 };
45 assertEquals(0, distance.compute(zero, zero), 0d);
46 }
47
48 @Test
49 void test() {
50 double expected = 0.65; //0.2 + 0.1 + 0.1 + 0.2 + 0.05 + 0.0;
51 assertEquals(expected, distance.compute(a, b), 1e-10);
52 assertEquals(expected, distance.compute(b, a), 1e-10);
53 }
54 }