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.distribution;
17  
18  /**
19   * Test cases for BinomialDistribution.
20   * Extends IntegerDistributionAbstractTest.  See class javadoc for
21   * IntegerDistributionAbstractTest for details.
22   * 
23   * @version $Revision: 155427 $ $Date: 2005-02-26 06:11:52 -0700 (Sat, 26 Feb 2005) $
24   */
25  public class BinomialDistributionTest extends IntegerDistributionAbstractTest {
26      
27      /**
28       * Constructor for BinomialDistributionTest.
29       * @param name
30       */
31      public BinomialDistributionTest(String name) {
32          super(name);
33      }
34      
35      //-------------- Implementations for abstract methods -----------------------
36      
37      /** Creates the default discrete distribution instance to use in tests. */
38      public IntegerDistribution makeDistribution() {
39          return DistributionFactory.newInstance().createBinomialDistribution(10,0.70);
40      }
41      
42      /** Creates the default probability density test input values */
43      public int[] makeDensityTestPoints() {
44          return new int[] {-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
45      }
46      
47      /** Creates the default probability density test expected values */
48      public double[] makeDensityTestValues() {
49          return new double[] {0d, 0.0000d, 0.0001d, 0.0014d, 0.0090d, 0.0368d, 0.1029d, 
50                  0.2001d, 0.2668d, 0.2335d, 0.1211d, 0.0282d, 0d};
51      }
52      
53      /** Creates the default cumulative probability density test input values */
54      public int[] makeCumulativeTestPoints() {
55          return makeDensityTestPoints();
56      }
57      
58      /** Creates the default cumulative probability density test expected values */
59      public double[] makeCumulativeTestValues() {
60          return new double[] {0d, 0.0000d, 0.0001d, 0.0016d, 0.0106d, 0.0473d,
61                  0.1503d, 0.3504d, 0.6172d, 0.8507d, 0.9718d, 1d, 1d};
62          }
63      
64      /** Creates the default inverse cumulative probability test input values */
65      public double[] makeInverseCumulativeTestPoints() {
66          return new double[] {0, 0.001d, 0.010d, 0.025d, 0.050d, 0.100d, 0.999d,
67                  0.990d, 0.975d, 0.950d, 0.900d,1}; 
68          }
69      
70      /** Creates the default inverse cumulative probability density test expected values */
71      public int[] makeInverseCumulativeTestValues() {
72          return new int[] {-1, 1, 2, 3, 4, 4, 9, 9, 9, 8, 8, Integer.MAX_VALUE};
73      }
74  
75      //----------------- Additional test cases ---------------------------------
76     
77      /** Test degenerate case p = 0   */
78      public void testDegenerate0() throws Exception {
79          setDistribution(DistributionFactory.newInstance().createBinomialDistribution(5,0.0d));
80          setCumulativeTestPoints(new int[] {-1, 0, 1, 5, 10 });
81          setCumulativeTestValues(new double[] {0d, 1d, 1d, 1d, 1d});
82          setDensityTestPoints(new int[] {-1, 0, 1, 10, 11});
83          setDensityTestValues(new double[] {0d, 1d, 0d, 0d, 0d});
84          setInverseCumulativeTestPoints(new double[] {0.1d, 0.5d});
85          setInverseCumulativeTestValues(new int[] {-1, -1});
86          verifyDensities();
87          verifyCumulativeProbabilities();
88          verifyInverseCumulativeProbabilities();     
89      }
90      
91      /** Test degenerate case p = 1   */
92      public void testDegenerate1() throws Exception {
93          setDistribution(DistributionFactory.newInstance().createBinomialDistribution(5,1.0d));
94          setCumulativeTestPoints(new int[] {-1, 0, 1, 2, 5, 10 });
95          setCumulativeTestValues(new double[] {0d, 0d, 0d, 0d, 1d, 1d});
96          setDensityTestPoints(new int[] {-1, 0, 1, 2, 5, 10});
97          setDensityTestValues(new double[] {0d, 0d, 0d, 0d, 1d, 0d});
98          setInverseCumulativeTestPoints(new double[] {0.1d, 0.5d});
99          setInverseCumulativeTestValues(new int[] {4, 4});
100         verifyDensities();
101         verifyCumulativeProbabilities();
102         verifyInverseCumulativeProbabilities();     
103     }
104 
105 }