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Java > Open Source Codes > org > apache > commons > math > stat > descriptive > rank > PercentileTest


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.rank;
17
18 import junit.framework.Test;
19 import junit.framework.TestSuite;
20
21 import org.apache.commons.math.stat.descriptive.UnivariateStatistic;
22 import org.apache.commons.math.stat.descriptive.UnivariateStatisticAbstractTest;
23
24 /**
25  * Test cases for the {@link UnivariateStatistic} class.
26  * @version $Revision$ $Date: 2005-02-26 05:11:52 -0800 (Sat, 26 Feb 2005) $
27  */
28 public class PercentileTest extends UnivariateStatisticAbstractTest{
29
30     protected Percentile stat;
31     
32     /**
33      * @param name
34      */
35     public PercentileTest(String JavaDoc name) {
36         super(name);
37     }
38
39     public static Test suite() {
40         TestSuite suite = new TestSuite(PercentileTest.class);
41         suite.setName("Percentile 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 Percentile(95.0);
50     }
51
52     /* (non-Javadoc)
53      * @see org.apache.commons.math.stat.descriptive.UnivariateStatisticAbstractTest#expectedValue()
54      */
55     public double expectedValue() {
56         return this.percentile95;
57     }
58
59     public void testHighPercentile(){
60         double[] d = new double[]{1, 2, 3};
61         Percentile p = new Percentile(75);
62         assertEquals(3.0, p.evaluate(d), 1.0e-5);
63     }
64     
65     public void testPercentile() {
66         double[] d = new double[] {1, 3, 2, 4};
67         Percentile p = new Percentile(30);
68         assertEquals(1.5, p.evaluate(d), 1.0e-5);
69         p.setQuantile(25);
70         assertEquals(1.25, p.evaluate(d), 1.0e-5);
71         p.setQuantile(75);
72         assertEquals(3.75, p.evaluate(d), 1.0e-5);
73         p.setQuantile(50);
74         assertEquals(2.5, p.evaluate(d), 1.0e-5);
75     }
76     
77     public void testNISTExample() {
78         double[] d = new double[] {95.1772, 95.1567, 95.1937, 95.1959,
79                 95.1442, 95.0610, 95.1591, 95.1195, 95.1772, 95.0925, 95.1990, 95.1682
80         };
81         Percentile p = new Percentile(90);
82         assertEquals(95.1981, p.evaluate(d), 1.0e-4);
83         assertEquals(95.1990, p.evaluate(d,0,d.length, 100d), 0);
84     }
85     
86     public void test5() {
87         Percentile percentile = new Percentile(5);
88         assertEquals(this.percentile5, percentile.evaluate(testArray), getTolerance());
89     }
90     
91     public void testNullEmpty() {
92         Percentile percentile = new Percentile(50);
93         double[] nullArray = null;
94         double[] emptyArray = new double[] {};
95         try {
96             percentile.evaluate(nullArray);
97             fail("Expecting IllegalArgumentException for null array");
98         } catch (IllegalArgumentException JavaDoc ex) {
99             // expected
100 }
101         assertTrue(Double.isNaN(percentile.evaluate(emptyArray)));
102     }
103     
104     public void testSingleton() {
105         Percentile percentile = new Percentile(50);
106         double[] singletonArray = new double[] {1d};
107         assertEquals(1d, percentile.evaluate(singletonArray), 0);
108         assertEquals(1d, percentile.evaluate(singletonArray, 0, 1), 0);
109         assertEquals(1d, percentile.evaluate(singletonArray, 0, 1, 5), 0);
110         assertEquals(1d, percentile.evaluate(singletonArray, 0, 1, 100), 0);
111         assertTrue(Double.isNaN(percentile.evaluate(singletonArray, 0, 0)));
112     }
113     
114     public void testSpecialValues() {
115         Percentile percentile = new Percentile(50);
116         double[] specialValues = new double[] {0d, 1d, 2d, 3d, 4d, Double.NaN};
117         assertEquals(2.5d, percentile.evaluate(specialValues), 0);
118         specialValues = new double[] {Double.NEGATIVE_INFINITY, 1d, 2d, 3d,
119                 Double.NaN, Double.POSITIVE_INFINITY};
120         assertEquals(2.5d, percentile.evaluate(specialValues), 0);
121         specialValues = new double[] {1d, 1d, Double.POSITIVE_INFINITY,
122                 Double.POSITIVE_INFINITY};
123         assertTrue(Double.isInfinite(percentile.evaluate(specialValues)));
124         specialValues = new double[] {1d, 1d, Double.NaN,
125                 Double.NaN};
126         assertTrue(Double.isNaN(percentile.evaluate(specialValues)));
127         specialValues = new double[] {1d, 1d, Double.NEGATIVE_INFINITY,
128                 Double.NEGATIVE_INFINITY};
129         // Interpolation results in NEGATIVE_INFINITY + POSITIVE_INFINITY
130 assertTrue(Double.isNaN(percentile.evaluate(specialValues)));
131     }
132     
133     public void testSetQuantile() {
134         Percentile percentile = new Percentile(10);
135         percentile.setQuantile(100); // OK
136 assertEquals(100, percentile.getQuantile(), 0);
137         try {
138             percentile.setQuantile(0);
139             fail("Expecting IllegalArgumentException");
140         } catch (IllegalArgumentException JavaDoc ex) {
141             // expected
142 }
143         try {
144             percentile = new Percentile(0);
145             fail("Expecting IllegalArgumentException");
146         } catch (IllegalArgumentException JavaDoc ex) {
147             // expected
148 }
149     }
150     
151 }
152
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