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.distribution;
18  
19  /**
20   * Test cases for BinomialDistribution.
21   * Extends IntegerDistributionAbstractTest.  See class javadoc for
22   * IntegerDistributionAbstractTest for details.
23   * 
24   * @version $Revision: 545192 $ $Date: 2007-06-07 07:35:04 -0700 (Thu, 07 Jun 2007) $
25   */
26  public class BinomialDistributionTest extends IntegerDistributionAbstractTest {
27      
28      /**
29       * Constructor for BinomialDistributionTest.
30       * @param name
31       */
32      public BinomialDistributionTest(String name) {
33          super(name);
34      }
35      
36      //-------------- Implementations for abstract methods -----------------------
37      
38      /** Creates the default discrete distribution instance to use in tests. */
39      public IntegerDistribution makeDistribution() {
40          return new BinomialDistributionImpl(10,0.70);
41      }
42      
43      /** Creates the default probability density test input values */
44      public int[] makeDensityTestPoints() {
45          return new int[] {-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
46      }
47      
48      /** Creates the default probability density test expected values */
49      public double[] makeDensityTestValues() {
50          return new double[] {0d, 0.0000d, 0.0001d, 0.0014d, 0.0090d, 0.0368d, 0.1029d, 
51                  0.2001d, 0.2668d, 0.2335d, 0.1211d, 0.0282d, 0d};
52      }
53      
54      /** Creates the default cumulative probability density test input values */
55      public int[] makeCumulativeTestPoints() {
56          return makeDensityTestPoints();
57      }
58      
59      /** Creates the default cumulative probability density test expected values */
60      public double[] makeCumulativeTestValues() {
61          return new double[] {0d, 0.0000d, 0.0001d, 0.0016d, 0.0106d, 0.0473d,
62                  0.1503d, 0.3504d, 0.6172d, 0.8507d, 0.9718d, 1d, 1d};
63          }
64      
65      /** Creates the default inverse cumulative probability test input values */
66      public double[] makeInverseCumulativeTestPoints() {
67          return new double[] {0, 0.001d, 0.010d, 0.025d, 0.050d, 0.100d, 0.999d,
68                  0.990d, 0.975d, 0.950d, 0.900d,1}; 
69          }
70      
71      /** Creates the default inverse cumulative probability density test expected values */
72      public int[] makeInverseCumulativeTestValues() {
73          return new int[] {-1, 1, 2, 3, 4, 4, 9, 9, 9, 8, 8, Integer.MAX_VALUE};
74      }
75  
76      //----------------- Additional test cases ---------------------------------
77     
78      /** Test degenerate case p = 0   */
79      public void testDegenerate0() throws Exception {
80          setDistribution(new BinomialDistributionImpl(5,0.0d));
81          setCumulativeTestPoints(new int[] {-1, 0, 1, 5, 10 });
82          setCumulativeTestValues(new double[] {0d, 1d, 1d, 1d, 1d});
83          setDensityTestPoints(new int[] {-1, 0, 1, 10, 11});
84          setDensityTestValues(new double[] {0d, 1d, 0d, 0d, 0d});
85          setInverseCumulativeTestPoints(new double[] {0.1d, 0.5d});
86          setInverseCumulativeTestValues(new int[] {-1, -1});
87          verifyDensities();
88          verifyCumulativeProbabilities();
89          verifyInverseCumulativeProbabilities();     
90      }
91      
92      /** Test degenerate case p = 1   */
93      public void testDegenerate1() throws Exception {
94          setDistribution(new BinomialDistributionImpl(5,1.0d));
95          setCumulativeTestPoints(new int[] {-1, 0, 1, 2, 5, 10 });
96          setCumulativeTestValues(new double[] {0d, 0d, 0d, 0d, 1d, 1d});
97          setDensityTestPoints(new int[] {-1, 0, 1, 2, 5, 10});
98          setDensityTestValues(new double[] {0d, 0d, 0d, 0d, 1d, 0d});
99          setInverseCumulativeTestPoints(new double[] {0.1d, 0.5d});
100         setInverseCumulativeTestValues(new int[] {4, 4});
101         verifyDensities();
102         verifyCumulativeProbabilities();
103         verifyInverseCumulativeProbabilities();     
104     }
105 
106 }