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