1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16 package org.apache.commons.math.distribution;
17
18 import junit.framework.TestCase;
19
20 /**
21 * Abstract base class for {@link IntegerDistribution} tests.
22 * <p>
23 * To create a concrete test class for an integer distribution implementation,
24 * implement makeDistribution() to return a distribution instance to use in
25 * tests and each of the test data generation methods below. In each case, the
26 * test points and test values arrays returned represent parallel arrays of
27 * inputs and expected values for the distribution returned by makeDistribution().
28 * <p>
29 * makeDensityTestPoints() -- arguments used to test probability density calculation
30 * makeDensityTestValues() -- expected probability densities
31 * makeCumulativeTestPoints() -- arguments used to test cumulative probabilities
32 * makeCumulativeTestValues() -- expected cumulative probabilites
33 * makeInverseCumulativeTestPoints() -- arguments used to test inverse cdf evaluation
34 * makeInverseCumulativeTestValues() -- expected inverse cdf values
35 * <p>
36 * To implement additional test cases with different distribution instances and test data,
37 * use the setXxx methods for the instance data in test cases and call the verifyXxx methods
38 * to verify results.
39 *
40 * @version $Revision: 155427 $ $Date: 2005-02-26 06:11:52 -0700 (Sat, 26 Feb 2005) $
41 */
42 public abstract class IntegerDistributionAbstractTest extends TestCase {
43
44
45 /** Discrete distribution instance used to perform tests */
46 private IntegerDistribution distribution;
47
48 /** Tolerance used in comparing expected and returned values */
49 private double tolerance = 1E-4;
50
51 /** Arguments used to test probability density calculations */
52 private int[] densityTestPoints;
53
54 /** Values used to test probability density calculations */
55 private double[] densityTestValues;
56
57 /** Arguments used to test cumulative probability density calculations */
58 private int[] cumulativeTestPoints;
59
60 /** Values used to test cumulative probability density calculations */
61 private double[] cumulativeTestValues;
62
63 /** Arguments used to test inverse cumulative probability density calculations */
64 private double[] inverseCumulativeTestPoints;
65
66 /** Values used to test inverse cumulative probability density calculations */
67 private int[] inverseCumulativeTestValues;
68
69
70
71 /**
72 * Constructor for IntegerDistributionAbstractTest.
73 * @param name
74 */
75 public IntegerDistributionAbstractTest(String name) {
76 super(name);
77 }
78
79
80
81 /** Creates the default discrete distribution instance to use in tests. */
82 public abstract IntegerDistribution makeDistribution();
83
84 /** Creates the default probability density test input values */
85 public abstract int[] makeDensityTestPoints();
86
87 /** Creates the default probability density test expected values */
88 public abstract double[] makeDensityTestValues();
89
90 /** Creates the default cumulative probability density test input values */
91 public abstract int[] makeCumulativeTestPoints();
92
93 /** Creates the default cumulative probability density test expected values */
94 public abstract double[] makeCumulativeTestValues();
95
96 /** Creates the default inverse cumulative probability test input values */
97 public abstract double[] makeInverseCumulativeTestPoints();
98
99 /** Creates the default inverse cumulative probability density test expected values */
100 public abstract int[] makeInverseCumulativeTestValues();
101
102
103
104 /**
105 * Setup sets all test instance data to default values
106 */
107 protected void setUp() throws Exception {
108 super.setUp();
109 distribution = makeDistribution();
110 densityTestPoints = makeDensityTestPoints();
111 densityTestValues = makeDensityTestValues();
112 cumulativeTestPoints = makeCumulativeTestPoints();
113 cumulativeTestValues = makeCumulativeTestValues();
114 inverseCumulativeTestPoints = makeInverseCumulativeTestPoints();
115 inverseCumulativeTestValues = makeInverseCumulativeTestValues();
116 }
117
118 /**
119 * Cleans up test instance data
120 */
121 protected void tearDown() throws Exception {
122 super.tearDown();
123 distribution = null;
124 densityTestPoints = null;
125 densityTestValues = null;
126 cumulativeTestPoints = null;
127 cumulativeTestValues = null;
128 inverseCumulativeTestPoints = null;
129 inverseCumulativeTestValues = null;
130 }
131
132
133
134 /**
135 * Verifies that probability density calculations match exptected values
136 * using current test instance data
137 */
138 protected void verifyDensities() throws Exception {
139 for (int i = 0; i < densityTestPoints.length; i++) {
140 assertEquals("Incorrect density value returned for " + densityTestPoints[i],
141 densityTestValues[i],
142 distribution.probability(densityTestPoints[i]), tolerance);
143 }
144 }
145
146 /**
147 * Verifies that cumulative probability density calculations match exptected values
148 * using current test instance data
149 */
150 protected void verifyCumulativeProbabilities() throws Exception {
151 for (int i = 0; i < cumulativeTestPoints.length; i++) {
152 assertEquals("Incorrect cumulative probability value returned for " + cumulativeTestPoints[i],
153 cumulativeTestValues[i],
154 distribution.cumulativeProbability(cumulativeTestPoints[i]), tolerance);
155 }
156 }
157
158 /**
159 * Verifies that inverse cumulative probability density calculations match exptected values
160 * using current test instance data
161 */
162 protected void verifyInverseCumulativeProbabilities() throws Exception {
163 for (int i = 0; i < inverseCumulativeTestPoints.length; i++) {
164 assertEquals("Incorrect inverse cumulative probability value returned for "
165 + inverseCumulativeTestPoints[i], inverseCumulativeTestValues[i],
166 distribution.inverseCumulativeProbability(inverseCumulativeTestPoints[i]));
167 }
168 }
169
170
171
172 /**
173 * Verifies that probability density calculations match exptected values
174 * using default test instance data
175 */
176 public void testDensities() throws Exception {
177 verifyDensities();
178 }
179
180 /**
181 * Verifies that cumulative probability density calculations match exptected values
182 * using default test instance data
183 */
184 public void testCumulativeProbabilities() throws Exception {
185 verifyCumulativeProbabilities();
186 }
187
188 /**
189 * Verifies that inverse cumulative probability density calculations match exptected values
190 * using default test instance data
191 */
192 public void testInverseCumulativeProbabilities() throws Exception {
193 verifyInverseCumulativeProbabilities();
194 }
195
196 /**
197 * Verifies that illegal arguments are correctly handled
198 */
199 public void testIllegalArguments() throws Exception {
200 try {
201 distribution.cumulativeProbability(1, 0);
202 fail("Expecting IllegalArgumentException for bad cumulativeProbability interval");
203 } catch (IllegalArgumentException ex) {
204
205 }
206 try {
207 distribution.inverseCumulativeProbability(-1);
208 fail("Expecting IllegalArgumentException for p = -1");
209 } catch (IllegalArgumentException ex) {
210
211 }
212 try {
213 distribution.inverseCumulativeProbability(2);
214 fail("Expecting IllegalArgumentException for p = 2");
215 } catch (IllegalArgumentException ex) {
216
217 }
218 }
219
220
221 /**
222 * @return Returns the cumulativeTestPoints.
223 */
224 protected int[] getCumulativeTestPoints() {
225 return cumulativeTestPoints;
226 }
227
228 /**
229 * @param cumulativeTestPoints The cumulativeTestPoints to set.
230 */
231 protected void setCumulativeTestPoints(int[] cumulativeTestPoints) {
232 this.cumulativeTestPoints = cumulativeTestPoints;
233 }
234
235 /**
236 * @return Returns the cumulativeTestValues.
237 */
238 protected double[] getCumulativeTestValues() {
239 return cumulativeTestValues;
240 }
241
242 /**
243 * @param cumulativeTestValues The cumulativeTestValues to set.
244 */
245 protected void setCumulativeTestValues(double[] cumulativeTestValues) {
246 this.cumulativeTestValues = cumulativeTestValues;
247 }
248
249 /**
250 * @return Returns the densityTestPoints.
251 */
252 protected int[] getDensityTestPoints() {
253 return densityTestPoints;
254 }
255
256 /**
257 * @param densityTestPoints The densityTestPoints to set.
258 */
259 protected void setDensityTestPoints(int[] densityTestPoints) {
260 this.densityTestPoints = densityTestPoints;
261 }
262
263 /**
264 * @return Returns the densityTestValues.
265 */
266 protected double[] getDensityTestValues() {
267 return densityTestValues;
268 }
269
270 /**
271 * @param densityTestValues The densityTestValues to set.
272 */
273 protected void setDensityTestValues(double[] densityTestValues) {
274 this.densityTestValues = densityTestValues;
275 }
276
277 /**
278 * @return Returns the distribution.
279 */
280 protected IntegerDistribution getDistribution() {
281 return distribution;
282 }
283
284 /**
285 * @param distribution The distribution to set.
286 */
287 protected void setDistribution(IntegerDistribution distribution) {
288 this.distribution = distribution;
289 }
290
291 /**
292 * @return Returns the inverseCumulativeTestPoints.
293 */
294 protected double[] getInverseCumulativeTestPoints() {
295 return inverseCumulativeTestPoints;
296 }
297
298 /**
299 * @param inverseCumulativeTestPoints The inverseCumulativeTestPoints to set.
300 */
301 protected void setInverseCumulativeTestPoints(double[] inverseCumulativeTestPoints) {
302 this.inverseCumulativeTestPoints = inverseCumulativeTestPoints;
303 }
304
305 /**
306 * @return Returns the inverseCumulativeTestValues.
307 */
308 protected int[] getInverseCumulativeTestValues() {
309 return inverseCumulativeTestValues;
310 }
311
312 /**
313 * @param inverseCumulativeTestValues The inverseCumulativeTestValues to set.
314 */
315 protected void setInverseCumulativeTestValues(int[] inverseCumulativeTestValues) {
316 this.inverseCumulativeTestValues = inverseCumulativeTestValues;
317 }
318
319 /**
320 * @return Returns the tolerance.
321 */
322 protected double getTolerance() {
323 return tolerance;
324 }
325
326 /**
327 * @param tolerance The tolerance to set.
328 */
329 protected void setTolerance(double tolerance) {
330 this.tolerance = tolerance;
331 }
332
333 }