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 * https://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
18 /*
19 * This is not the original file distributed by the Apache Software Foundation
20 * It has been modified by the Hipparchus project
21 */
22
23 package org.hipparchus.distribution.discrete;
24
25 import org.hipparchus.distribution.IntegerDistribution;
26 import org.hipparchus.exception.MathIllegalArgumentException;
27 import org.junit.Assert;
28 import org.junit.Test;
29
30 /**
31 * Test cases for UniformIntegerDistribution.
32 */
33 public class UniformIntegerDistributionTest extends IntegerDistributionAbstractTest {
34
35 // --- Override tolerance -------------------------------------------------
36
37 @Override
38 public void setUp() {
39 super.setUp();
40 setTolerance(1e-9);
41 }
42
43 //--- Implementations for abstract methods --------------------------------
44
45 /** Creates the default discrete distribution instance to use in tests. */
46 @Override
47 public IntegerDistribution makeDistribution() {
48 return new UniformIntegerDistribution(-3, 5);
49 }
50
51 /** Creates the default probability density test input values. */
52 @Override
53 public int[] makeDensityTestPoints() {
54 return new int[] {-4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6};
55 }
56
57 /** Creates the default probability density test expected values. */
58 @Override
59 public double[] makeDensityTestValues() {
60 double d = 1.0 / (5 - -3 + 1);
61 return new double[] {0, d, d, d, d, d, d, d, d, d, 0};
62 }
63
64 /** Creates the default cumulative probability density test input values. */
65 @Override
66 public int[] makeCumulativeTestPoints() {
67 return makeDensityTestPoints();
68 }
69
70 /** Creates the default cumulative probability density test expected values. */
71 @Override
72 public double[] makeCumulativeTestValues() {
73 return new double[] {0, 1 / 9.0, 2 / 9.0, 3 / 9.0, 4 / 9.0, 5 / 9.0,
74 6 / 9.0, 7 / 9.0, 8 / 9.0, 1, 1};
75 }
76
77 /** Creates the default inverse cumulative probability test input values */
78 @Override
79 public double[] makeInverseCumulativeTestPoints() {
80 return new double[] {0, 0.001, 0.010, 0.025, 0.050, 0.100, 0.200,
81 0.5, 0.999, 0.990, 0.975, 0.950, 0.900, 1};
82 }
83
84 /** Creates the default inverse cumulative probability density test expected values */
85 @Override
86 public int[] makeInverseCumulativeTestValues() {
87 return new int[] {-3, -3, -3, -3, -3, -3, -2, 1, 5, 5, 5, 5, 5, 5};
88 }
89
90 //--- Additional test cases -----------------------------------------------
91
92 /** Test mean/variance. */
93 @Test
94 public void testMoments() {
95 UniformIntegerDistribution dist;
96
97 dist = new UniformIntegerDistribution(0, 5);
98 Assert.assertEquals(dist.getNumericalMean(), 2.5, 0);
99 Assert.assertEquals(dist.getNumericalVariance(), 35 / 12.0, 0);
100
101 dist = new UniformIntegerDistribution(0, 1);
102 Assert.assertEquals(dist.getNumericalMean(), 0.5, 0);
103 Assert.assertEquals(dist.getNumericalVariance(), 3 / 12.0, 0);
104 }
105
106 // MATH-1141
107 @Test
108 public void testPreconditionUpperBoundInclusive() {
109 try {
110 new UniformIntegerDistribution(1, 0);
111 } catch (MathIllegalArgumentException e) {
112 // Expected.
113 }
114
115 // Degenerate case is allowed.
116 new UniformIntegerDistribution(0, 0);
117 }
118 }