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.stat.descriptive.moment;
18
19 import org.apache.commons.math4.legacy.stat.descriptive.StorelessUnivariateStatisticAbstractTest;
20 import org.apache.commons.math4.legacy.stat.descriptive.UnivariateStatistic;
21 import org.junit.Assert;
22 import org.junit.Test;
23
24 /**
25 * Test cases for the {@link UnivariateStatistic} class.
26 */
27 public class GeometricMeanTest extends StorelessUnivariateStatisticAbstractTest{
28
29 protected GeometricMean stat;
30
31 /**
32 * {@inheritDoc}
33 */
34 @Override
35 public UnivariateStatistic getUnivariateStatistic() {
36 return new GeometricMean();
37 }
38
39 /**
40 * {@inheritDoc}
41 */
42 @Override
43 public double expectedValue() {
44 return this.geoMean;
45 }
46
47 @Test
48 public void testSpecialValues() {
49 GeometricMean mean = new GeometricMean();
50 // empty
51 Assert.assertTrue(Double.isNaN(mean.getResult()));
52
53 // finite data
54 mean.increment(1d);
55 Assert.assertFalse(Double.isNaN(mean.getResult()));
56
57 // add 0 -- makes log sum blow to minus infinity, should make 0
58 mean.increment(0d);
59 Assert.assertEquals(0d, mean.getResult(), 0);
60
61 // add positive infinity - note the minus infinity above
62 mean.increment(Double.POSITIVE_INFINITY);
63 Assert.assertTrue(Double.isNaN(mean.getResult()));
64
65 // clear
66 mean.clear();
67 Assert.assertTrue(Double.isNaN(mean.getResult()));
68
69 // positive infinity by itself
70 mean.increment(Double.POSITIVE_INFINITY);
71 Assert.assertEquals(Double.POSITIVE_INFINITY, mean.getResult(), 0);
72
73 // negative value -- should make NaN
74 mean.increment(-2d);
75 Assert.assertTrue(Double.isNaN(mean.getResult()));
76 }
77 }