1 /*
2 * Copyright 2003-2004 The Apache Software Foundation.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.apache.commons.math.stat.descriptive.moment;
17
18 import junit.framework.Test;
19 import junit.framework.TestSuite;
20
21 import org.apache.commons.math.stat.descriptive.StorelessUnivariateStatisticAbstractTest;
22 import org.apache.commons.math.stat.descriptive.UnivariateStatistic;
23
24 /**
25 * Test cases for the {@link UnivariateStatistic} class.
26 * @version $Revision: 155427 $ $Date: 2005-02-26 06:11:52 -0700 (Sat, 26 Feb 2005) $
27 */
28 public class KurtosisTest extends StorelessUnivariateStatisticAbstractTest{
29
30 protected Kurtosis stat;
31
32 /**
33 * @param name
34 */
35 public KurtosisTest(String name) {
36 super(name);
37 }
38
39 public static Test suite() {
40 TestSuite suite = new TestSuite(KurtosisTest.class);
41 suite.setName("Kurtosis Tests");
42 return suite;
43 }
44
45 /* (non-Javadoc)
46 * @see org.apache.commons.math.stat.descriptive.UnivariateStatisticAbstractTest#getUnivariateStatistic()
47 */
48 public UnivariateStatistic getUnivariateStatistic() {
49 return new Kurtosis();
50 }
51
52 /* (non-Javadoc)
53 * @see org.apache.commons.math.stat.descriptive.UnivariateStatisticAbstractTest#expectedValue()
54 */
55 public double expectedValue() {
56 return this.kurt;
57 }
58
59 /**
60 * Make sure Double.NaN is returned iff n < 4
61 *
62 */
63 public void testNaN() {
64 Kurtosis kurt = new Kurtosis();
65 assertTrue(Double.isNaN(kurt.getResult()));
66 kurt.increment(1d);
67 assertTrue(Double.isNaN(kurt.getResult()));
68 kurt.increment(1d);
69 assertTrue(Double.isNaN(kurt.getResult()));
70 kurt.increment(1d);
71 assertTrue(Double.isNaN(kurt.getResult()));
72 kurt.increment(1d);
73 assertFalse(Double.isNaN(kurt.getResult()));
74 }
75
76 }