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16 package org.apache.commons.math.stat.descriptive;
17
18
19 import junit.framework.Test;
20 import junit.framework.TestCase;
21 import junit.framework.TestSuite;
22
23 import org.apache.commons.math.TestUtils;
24
29
30 public final class SummaryStatisticsImplTest extends TestCase {
31 private double one = 1;
32 private float twoF = 2;
33 private long twoL = 2;
34 private int three = 3;
35 private double mean = 2;
36 private double sumSq = 18;
37 private double sum = 8;
38 private double var = 0.666666666666666666667;
39 private double std = Math.sqrt(var);
40 private double n = 4;
41 private double min = 1;
42 private double max = 3;
43 private double tolerance = 10E-15;
44
45 protected SummaryStatistics u = null;
46
47 public SummaryStatisticsImplTest(String  name) {
48 super(name);
49 }
50
51 public void setUp() {
52 u = SummaryStatistics.newInstance();
53 }
54
55 public static Test suite() {
56 TestSuite suite = new TestSuite(SummaryStatisticsImplTest.class);
57 suite.setName("Frequency Tests");
58 return suite;
59 }
60
61
62 public void testStats() {
63 assertEquals("total count",0,u.getN(),tolerance);
64 u.addValue(one);
65 u.addValue(twoF);
66 u.addValue(twoL);
67 u.addValue(three);
68 assertEquals("N",n,u.getN(),tolerance);
69 assertEquals("sum",sum,u.getSum(),tolerance);
70 assertEquals("sumsq",sumSq,u.getSumsq(),tolerance);
71 assertEquals("var",var,u.getVariance(),tolerance);
72 assertEquals("std",std,u.getStandardDeviation(),tolerance);
73 assertEquals("mean",mean,u.getMean(),tolerance);
74 assertEquals("min",min,u.getMin(),tolerance);
75 assertEquals("max",max,u.getMax(),tolerance);
76 u.clear();
77 assertEquals("total count",0,u.getN(),tolerance);
78 }
79
80 public void testN0andN1Conditions() throws Exception {
81 assertTrue("Mean of n = 0 set should be NaN",
82 Double.isNaN( u.getMean() ) );
83 assertTrue("Standard Deviation of n = 0 set should be NaN",
84 Double.isNaN( u.getStandardDeviation() ) );
85 assertTrue("Variance of n = 0 set should be NaN",
86 Double.isNaN(u.getVariance() ) );
87
88
89 u.addValue(one);
90 assertTrue("mean should be one (n = 1)",
91 u.getMean() == one);
92 assertTrue("geometric should be one (n = 1) instead it is " + u.getGeometricMean(),
93 u.getGeometricMean() == one);
94 assertTrue("Std should be zero (n = 1)",
95 u.getStandardDeviation() == 0.0);
96 assertTrue("variance should be zero (n = 1)",
97 u.getVariance() == 0.0);
98
99
100 u.addValue(twoF);
101 assertTrue("Std should not be zero (n = 2)",
102 u.getStandardDeviation() != 0.0);
103 assertTrue("variance should not be zero (n = 2)",
104 u.getVariance() != 0.0);
105
106 }
107
108 public void testProductAndGeometricMean() throws Exception {
109 u.addValue( 1.0 );
110 u.addValue( 2.0 );
111 u.addValue( 3.0 );
112 u.addValue( 4.0 );
113
114 assertEquals( "Geometric mean not expected", 2.213364,
115 u.getGeometricMean(), 0.00001 );
116 }
117
118 public void testNaNContracts() {
119 double nan = Double.NaN;
120 assertTrue("mean not NaN",Double.isNaN(u.getMean()));
121 assertTrue("min not NaN",Double.isNaN(u.getMin()));
122 assertTrue("std dev not NaN",Double.isNaN(u.getStandardDeviation()));
123 assertTrue("var not NaN",Double.isNaN(u.getVariance()));
124 assertTrue("geom mean not NaN",Double.isNaN(u.getGeometricMean()));
125
126 u.addValue(1.0);
127
128 assertEquals( "mean not expected", 1.0,
129 u.getMean(), Double.MIN_VALUE);
130 assertEquals( "variance not expected", 0.0,
131 u.getVariance(), Double.MIN_VALUE);
132 assertEquals( "geometric mean not expected", 1.0,
133 u.getGeometricMean(), Double.MIN_VALUE);
134
135 u.addValue(-1.0);
136
137 assertTrue("geom mean not NaN",Double.isNaN(u.getGeometricMean()));
138
139 u.addValue(0.0);
140
141 assertTrue("geom mean not NaN",Double.isNaN(u.getGeometricMean()));
142
143 }
145
146 public void testGetSummary() {
147 StatisticalSummary summary = u.getSummary();
148 verifySummary(summary);
149 u.addValue(1d);
150 summary = u.getSummary();
151 verifySummary(summary);
152 u.addValue(2d);
153 summary = u.getSummary();
154 verifySummary(summary);
155 u.addValue(2d);
156 summary = u.getSummary();
157 verifySummary(summary);
158 }
159
160 public void testSerialization() {
161 TestUtils.checkSerializedEquality(u);
163 SummaryStatistics s = (SummaryStatistics) TestUtils.serializeAndRecover(u);
164 StatisticalSummary summary = s.getSummary();
165 verifySummary(summary);
166
167 u.addValue(2d);
169 u.addValue(1d);
170 u.addValue(3d);
171 u.addValue(4d);
172 u.addValue(5d);
173
174 TestUtils.checkSerializedEquality(u);
176 s = (SummaryStatistics) TestUtils.serializeAndRecover(u);
177 summary = s.getSummary();
178 verifySummary(summary);
179
180 }
181
182 public void testEqualsAndHashCode() {
183 SummaryStatistics t = null;
184 int emptyHash = u.hashCode();
185 assertTrue("reflexive", u.equals(u));
186 assertFalse("non-null compared to null", u.equals(t));
187 assertFalse("wrong type", u.equals(new Double (0)));
188 t = SummaryStatistics.newInstance();
189 assertTrue("empty instances should be equal", t.equals(u));
190 assertTrue("empty instances should be equal", u.equals(t));
191 assertEquals("empty hash code", emptyHash, t.hashCode());
192
193 u.addValue(2d);
195 u.addValue(1d);
196 u.addValue(3d);
197 u.addValue(4d);
198 assertFalse("different n's should make instances not equal", t.equals(u));
199 assertFalse("different n's should make instances not equal", u.equals(t));
200 assertTrue("different n's should make hashcodes different",
201 u.hashCode() != t.hashCode());
202
203 t.addValue(4d);
205 t.addValue(2d);
206 t.addValue(3d);
207 t.addValue(1d);
208 assertTrue("summaries based on same data should be equal", t.equals(u));
209 assertTrue("summaries based on same data should be equal", u.equals(t));
210 assertEquals("summaries based on same data should have same hashcodes",
211 u.hashCode(), t.hashCode());
212
213 u.clear();
215 t.clear();
216 assertTrue("empty instances should be equal", t.equals(u));
217 assertTrue("empty instances should be equal", u.equals(t));
218 assertEquals("empty hash code", emptyHash, t.hashCode());
219 assertEquals("empty hash code", emptyHash, u.hashCode());
220 }
221
222 private void verifySummary(StatisticalSummary s) {
223 assertEquals("N",s.getN(),u.getN());
224 TestUtils.assertEquals("sum",s.getSum(),u.getSum(),tolerance);
225 TestUtils.assertEquals("var",s.getVariance(),u.getVariance(),tolerance);
226 TestUtils.assertEquals("std",s.getStandardDeviation(),u.getStandardDeviation(),tolerance);
227 TestUtils.assertEquals("mean",s.getMean(),u.getMean(),tolerance);
228 TestUtils.assertEquals("min",s.getMin(),u.getMin(),tolerance);
229 TestUtils.assertEquals("max",s.getMax(),u.getMax(),tolerance);
230 }
231 }
232 |
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