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.math.stat.descriptive.moment;
18
19 import junit.framework.Test;
20 import junit.framework.TestSuite;
21
22 import org.apache.commons.math.stat.descriptive.StorelessUnivariateStatisticAbstractTest;
23 import org.apache.commons.math.stat.descriptive.UnivariateStatistic;
24
25 /**
26 * Test cases for the {@link UnivariateStatistic} class.
27 * @version $Revision: 480442 $ $Date: 2006-11-29 00:21:22 -0700 (Wed, 29 Nov 2006) $
28 */
29 public class GeometricMeanTest extends StorelessUnivariateStatisticAbstractTest{
30
31 protected GeometricMean stat;
32
33 /**
34 * @param name
35 */
36 public GeometricMeanTest(String name) {
37 super(name);
38 }
39
40 public static Test suite() {
41 TestSuite suite = new TestSuite(GeometricMeanTest.class);
42 suite.setName("Mean Tests");
43 return suite;
44 }
45
46 /* (non-Javadoc)
47 * @see org.apache.commons.math.stat.descriptive.UnivariateStatisticAbstractTest#getUnivariateStatistic()
48 */
49 public UnivariateStatistic getUnivariateStatistic() {
50 return new GeometricMean();
51 }
52
53 /* (non-Javadoc)
54 * @see org.apache.commons.math.stat.descriptive.UnivariateStatisticAbstractTest#expectedValue()
55 */
56 public double expectedValue() {
57 return this.geoMean;
58 }
59
60 public void testSpecialValues() {
61 GeometricMean mean = new GeometricMean();
62 // empty
63 assertTrue(Double.isNaN(mean.getResult()));
64
65 // finite data
66 mean.increment(1d);
67 assertFalse(Double.isNaN(mean.getResult()));
68
69 // add 0 -- makes log sum blow to minus infinity, should make 0
70 mean.increment(0d);
71 assertEquals(0d, mean.getResult(), 0);
72
73 // add positive infinity - note the minus infinity above
74 mean.increment(Double.POSITIVE_INFINITY);
75 assertTrue(Double.isNaN(mean.getResult()));
76
77 // clear
78 mean.clear();
79 assertTrue(Double.isNaN(mean.getResult()));
80
81 // positive infinity by itself
82 mean.increment(Double.POSITIVE_INFINITY);
83 assertEquals(Double.POSITIVE_INFINITY, mean.getResult(), 0);
84
85 // negative value -- should make NaN
86 mean.increment(-2d);
87 assertTrue(Double.isNaN(mean.getResult()));
88 }
89
90 }