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 KurtosisTest extends StorelessUnivariateStatisticAbstractTest{
28
29 protected Kurtosis stat;
30
31 /**
32 * {@inheritDoc}
33 */
34 @Override
35 public UnivariateStatistic getUnivariateStatistic() {
36 return new Kurtosis();
37 }
38
39 /**
40 * {@inheritDoc}
41 */
42 @Override
43 public double expectedValue() {
44 return this.kurt;
45 }
46
47 /**
48 * Make sure Double.NaN is returned iff n < 4
49 */
50 @Test
51 public void testNaN() {
52 Kurtosis kurt = new Kurtosis();
53 Assert.assertTrue(Double.isNaN(kurt.getResult()));
54 kurt.increment(1d);
55 Assert.assertTrue(Double.isNaN(kurt.getResult()));
56 kurt.increment(1d);
57 Assert.assertTrue(Double.isNaN(kurt.getResult()));
58 kurt.increment(1d);
59 Assert.assertTrue(Double.isNaN(kurt.getResult()));
60 kurt.increment(1d);
61 Assert.assertFalse(Double.isNaN(kurt.getResult()));
62 }
63 }