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.hipparchus.util.FastMath;
25 import org.junit.jupiter.api.Test;
26
27 import static org.junit.jupiter.api.Assertions.assertEquals;
28
29 /**
30 * Tests for {@link EuclideanDistance} class.
31 */
32 class EuclideanDistanceTest {
33 final DistanceMeasure distance = new EuclideanDistance();
34
35 @Test
36 void testZero() {
37 final double[] a = { 0, 1, -2, 3.4, 5, -6.7, 89 };
38 assertEquals(0, distance.compute(a, a), 0d);
39 }
40
41 @Test
42 void test() {
43 final double[] a = { 1, -2, 3, 4 };
44 final double[] b = { -5, -6, 7, 8 };
45 final double expected = FastMath.sqrt(84);
46 assertEquals(expected, distance.compute(a, b), 0d);
47 assertEquals(expected, distance.compute(b, a), 0d);
48 }
49 }