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.ranking;
18  
19  import org.apache.commons.math.TestUtils;
20  import org.apache.commons.math.random.JDKRandomGenerator;
21  import org.apache.commons.math.random.RandomGenerator;
22  
23  import junit.framework.TestCase;
24  
25  /**
26   * Test cases for NaturalRanking class
27   * 
28   * @since 2.0
29   * @version $Revision: 799857 $ $Date: 2009-08-01 09:07:12 -0400 (Sat, 01 Aug 2009) $
30   */
31  public class NaturalRankingTest extends TestCase {
32  
33      private final double[] exampleData = { 20, 17, 30, 42.3, 17, 50,
34              Double.NaN, Double.NEGATIVE_INFINITY, 17 };
35      private final double[] tiesFirst = { 0, 0, 2, 1, 4 };
36      private final double[] tiesLast = { 4, 4, 1, 0 };
37      private final double[] multipleNaNs = { 0, 1, Double.NaN, Double.NaN };
38      private final double[] multipleTies = { 3, 2, 5, 5, 6, 6, 1 };
39      private final double[] allSame = { 0, 0, 0, 0 };
40  
41      public NaturalRankingTest(String arg0) {
42          super(arg0);
43      }
44  
45      @Override
46      protected void setUp() throws Exception {
47          super.setUp();
48      }
49  
50      @Override
51      protected void tearDown() throws Exception {
52          super.tearDown();
53      }
54  
55      public void testDefault() { // Ties averaged, NaNs maximal
56          NaturalRanking ranking = new NaturalRanking();
57          double[] ranks = ranking.rank(exampleData);
58          double[] correctRanks = { 5, 3, 6, 7, 3, 8, 9, 1, 3 };
59          TestUtils.assertEquals(correctRanks, ranks, 0d);
60          ranks = ranking.rank(tiesFirst);
61          correctRanks = new double[] { 1.5, 1.5, 4, 3, 5 };
62          TestUtils.assertEquals(correctRanks, ranks, 0d);
63          ranks = ranking.rank(tiesLast);
64          correctRanks = new double[] { 3.5, 3.5, 2, 1 };
65          TestUtils.assertEquals(correctRanks, ranks, 0d);
66          ranks = ranking.rank(multipleNaNs);
67          correctRanks = new double[] { 1, 2, 3.5, 3.5 };
68          TestUtils.assertEquals(correctRanks, ranks, 0d);
69          ranks = ranking.rank(multipleTies);
70          correctRanks = new double[] { 3, 2, 4.5, 4.5, 6.5, 6.5, 1 };
71          TestUtils.assertEquals(correctRanks, ranks, 0d);
72          ranks = ranking.rank(allSame);
73          correctRanks = new double[] { 2.5, 2.5, 2.5, 2.5 };
74          TestUtils.assertEquals(correctRanks, ranks, 0d);
75      }
76  
77      public void testNaNsMaximalTiesMinimum() {
78          NaturalRanking ranking = new NaturalRanking(TiesStrategy.MINIMUM);
79          double[] ranks = ranking.rank(exampleData);
80          double[] correctRanks = { 5, 2, 6, 7, 2, 8, 9, 1, 2 };
81          TestUtils.assertEquals(correctRanks, ranks, 0d);
82          ranks = ranking.rank(tiesFirst);
83          correctRanks = new double[] { 1, 1, 4, 3, 5 };
84          TestUtils.assertEquals(correctRanks, ranks, 0d);
85          ranks = ranking.rank(tiesLast);
86          correctRanks = new double[] { 3, 3, 2, 1 };
87          TestUtils.assertEquals(correctRanks, ranks, 0d);
88          ranks = ranking.rank(multipleNaNs);
89          correctRanks = new double[] { 1, 2, 3, 3 };
90          TestUtils.assertEquals(correctRanks, ranks, 0d);
91          ranks = ranking.rank(multipleTies);
92          correctRanks = new double[] { 3, 2, 4, 4, 6, 6, 1 };
93          TestUtils.assertEquals(correctRanks, ranks, 0d);
94          ranks = ranking.rank(allSame);
95          correctRanks = new double[] { 1, 1, 1, 1 };
96          TestUtils.assertEquals(correctRanks, ranks, 0d);
97      }
98  
99      public void testNaNsRemovedTiesSequential() {
100         NaturalRanking ranking = new NaturalRanking(NaNStrategy.REMOVED,
101                 TiesStrategy.SEQUENTIAL);
102         double[] ranks = ranking.rank(exampleData);
103         double[] correctRanks = { 5, 2, 6, 7, 3, 8, 1, 4 };
104         TestUtils.assertEquals(correctRanks, ranks, 0d);
105         ranks = ranking.rank(tiesFirst);
106         correctRanks = new double[] { 1, 2, 4, 3, 5 };
107         TestUtils.assertEquals(correctRanks, ranks, 0d);
108         ranks = ranking.rank(tiesLast);
109         correctRanks = new double[] { 3, 4, 2, 1 };
110         TestUtils.assertEquals(correctRanks, ranks, 0d);
111         ranks = ranking.rank(multipleNaNs);
112         correctRanks = new double[] { 1, 2 };
113         TestUtils.assertEquals(correctRanks, ranks, 0d);
114         ranks = ranking.rank(multipleTies);
115         correctRanks = new double[] { 3, 2, 4, 5, 6, 7, 1 };
116         TestUtils.assertEquals(correctRanks, ranks, 0d);
117         ranks = ranking.rank(allSame);
118         correctRanks = new double[] { 1, 2, 3, 4 };
119         TestUtils.assertEquals(correctRanks, ranks, 0d);
120     }
121 
122     public void testNaNsMinimalTiesMaximum() {
123         NaturalRanking ranking = new NaturalRanking(NaNStrategy.MINIMAL,
124                 TiesStrategy.MAXIMUM);
125         double[] ranks = ranking.rank(exampleData);
126         double[] correctRanks = { 6, 5, 7, 8, 5, 9, 2, 2, 5 };
127         TestUtils.assertEquals(correctRanks, ranks, 0d);
128         ranks = ranking.rank(tiesFirst);
129         correctRanks = new double[] { 2, 2, 4, 3, 5 };
130         TestUtils.assertEquals(correctRanks, ranks, 0d);
131         ranks = ranking.rank(tiesLast);
132         correctRanks = new double[] { 4, 4, 2, 1 };
133         TestUtils.assertEquals(correctRanks, ranks, 0d);
134         ranks = ranking.rank(multipleNaNs);
135         correctRanks = new double[] { 3, 4, 2, 2 };
136         TestUtils.assertEquals(correctRanks, ranks, 0d);
137         ranks = ranking.rank(multipleTies);
138         correctRanks = new double[] { 3, 2, 5, 5, 7, 7, 1 };
139         TestUtils.assertEquals(correctRanks, ranks, 0d);
140         ranks = ranking.rank(allSame);
141         correctRanks = new double[] { 4, 4, 4, 4 };
142         TestUtils.assertEquals(correctRanks, ranks, 0d);
143     }
144 
145     public void testNaNsMinimalTiesAverage() {
146         NaturalRanking ranking = new NaturalRanking(NaNStrategy.MINIMAL);
147         double[] ranks = ranking.rank(exampleData);
148         double[] correctRanks = { 6, 4, 7, 8, 4, 9, 1.5, 1.5, 4 };
149         TestUtils.assertEquals(correctRanks, ranks, 0d);
150         ranks = ranking.rank(tiesFirst);
151         correctRanks = new double[] { 1.5, 1.5, 4, 3, 5 };
152         TestUtils.assertEquals(correctRanks, ranks, 0d);
153         ranks = ranking.rank(tiesLast);
154         correctRanks = new double[] { 3.5, 3.5, 2, 1 };
155         TestUtils.assertEquals(correctRanks, ranks, 0d);
156         ranks = ranking.rank(multipleNaNs);
157         correctRanks = new double[] { 3, 4, 1.5, 1.5 };
158         TestUtils.assertEquals(correctRanks, ranks, 0d);
159         ranks = ranking.rank(multipleTies);
160         correctRanks = new double[] { 3, 2, 4.5, 4.5, 6.5, 6.5, 1 };
161         TestUtils.assertEquals(correctRanks, ranks, 0d);
162         ranks = ranking.rank(allSame);
163         correctRanks = new double[] { 2.5, 2.5, 2.5, 2.5 };
164         TestUtils.assertEquals(correctRanks, ranks, 0d);
165     }
166 
167     public void testNaNsFixedTiesRandom() {
168         RandomGenerator randomGenerator = new JDKRandomGenerator();
169         randomGenerator.setSeed(1000);
170         NaturalRanking ranking = new NaturalRanking(NaNStrategy.FIXED,
171                 randomGenerator);
172         double[] ranks = ranking.rank(exampleData);
173         double[] correctRanks = { 5, 4, 6, 7, 3, 8, Double.NaN, 1, 4 };
174         TestUtils.assertEquals(correctRanks, ranks, 0d);
175         ranks = ranking.rank(tiesFirst);
176         correctRanks = new double[] { 1, 1, 4, 3, 5 };
177         TestUtils.assertEquals(correctRanks, ranks, 0d);
178         ranks = ranking.rank(tiesLast);
179         correctRanks = new double[] { 3, 4, 2, 1 };
180         TestUtils.assertEquals(correctRanks, ranks, 0d);
181         ranks = ranking.rank(multipleNaNs);
182         correctRanks = new double[] { 1, 2, Double.NaN, Double.NaN };
183         TestUtils.assertEquals(correctRanks, ranks, 0d);
184         ranks = ranking.rank(multipleTies);
185         correctRanks = new double[] { 3, 2, 5, 5, 7, 6, 1 };
186         TestUtils.assertEquals(correctRanks, ranks, 0d);
187         ranks = ranking.rank(allSame);
188         correctRanks = new double[] { 1, 3, 4, 4 };
189         TestUtils.assertEquals(correctRanks, ranks, 0d);
190     }
191 
192     public void testNaNsAndInfs() {
193         double[] data = { 0, Double.POSITIVE_INFINITY, Double.NaN,
194                 Double.NEGATIVE_INFINITY };
195         NaturalRanking ranking = new NaturalRanking(NaNStrategy.MAXIMAL);
196         double[] ranks = ranking.rank(data);
197         double[] correctRanks = new double[] { 2, 3.5, 3.5, 1 };
198         TestUtils.assertEquals(correctRanks, ranks, 0d);
199         ranking = new NaturalRanking(NaNStrategy.MINIMAL);
200         ranks = ranking.rank(data);
201         correctRanks = new double[] { 3, 4, 1.5, 1.5 };
202         TestUtils.assertEquals(correctRanks, ranks, 0d);
203     }
204 }