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.stat.descriptive.moment;
23
24 import org.hipparchus.stat.descriptive.StorelessUnivariateStatisticAbstractTest;
25 import org.junit.Assert;
26 import org.junit.Test;
27
28 /**
29 * Test cases for the {@link GeometricMean} class.
30 */
31 public class GeometricMeanTest extends StorelessUnivariateStatisticAbstractTest{
32
33 @Override
34 public GeometricMean getUnivariateStatistic() {
35 return new GeometricMean();
36 }
37
38 @Override
39 public double expectedValue() {
40 return this.geoMean;
41 }
42
43 @Test
44 public void testSpecialValues() {
45 GeometricMean mean = getUnivariateStatistic();
46 // empty
47 Assert.assertTrue(Double.isNaN(mean.getResult()));
48
49 // finite data
50 mean.increment(1d);
51 Assert.assertFalse(Double.isNaN(mean.getResult()));
52
53 // add 0 -- makes log sum blow to minus infinity, should make 0
54 mean.increment(0d);
55 Assert.assertEquals(0d, mean.getResult(), 0);
56
57 // add positive infinity - note the minus infinity above
58 mean.increment(Double.POSITIVE_INFINITY);
59 Assert.assertTrue(Double.isNaN(mean.getResult()));
60
61 // clear
62 mean.clear();
63 Assert.assertTrue(Double.isNaN(mean.getResult()));
64
65 // positive infinity by itself
66 mean.increment(Double.POSITIVE_INFINITY);
67 Assert.assertEquals(Double.POSITIVE_INFINITY, mean.getResult(), 0);
68
69 // negative value -- should make NaN
70 mean.increment(-2d);
71 Assert.assertTrue(Double.isNaN(mean.getResult()));
72 }
73
74 }