/*******************************************************************************
* Copyright (c) 2010 Haifeng Li
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*******************************************************************************/
package smile.stat.distribution;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.junit.Assert.*;
/**
*
* @author Haifeng Li
*/
public class PoissonDistributionTest {
public PoissonDistributionTest() {
}
@BeforeClass
public static void setUpClass() throws Exception {
}
@AfterClass
public static void tearDownClass() throws Exception {
}
@Before
public void setUp() {
}
@After
public void tearDown() {
}
/**
* Test of constructor, of class PoissonDistribution.
*/
@Test
public void testPoissonDistribution() {
System.out.println("PoissonDistribution");
PoissonDistribution instance = new PoissonDistribution(5.5);
int[] data = new int[1000];
for (int i = 0; i < data.length; i++)
data[i] = (int) instance.rand();
PoissonDistribution est = new PoissonDistribution(data);
assertEquals(5.5, est.getLambda(), 1.5E-1);
}
/**
* Test of npara method, of class Poisson.
*/
@Test
public void testNpara() {
System.out.println("npara");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertEquals(1, instance.npara());
}
/**
* Test of mean method, of class Poisson.
*/
@Test
public void testMean() {
System.out.println("mean");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertEquals(3.5, instance.mean(), 1E-7);
}
/**
* Test of var method, of class Poisson.
*/
@Test
public void testVar() {
System.out.println("var");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertEquals(3.5, instance.var(), 1E-7);
}
/**
* Test of sd method, of class Poisson.
*/
@Test
public void testSd() {
System.out.println("sd");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertEquals(Math.sqrt(3.5), instance.sd(), 1E-7);
}
/**
* Test of entropy method, of class Poisson.
*/
@Test
public void testEntropy() {
System.out.println("entropy");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertEquals(2.016878, instance.entropy(), 1E-6);
}
/**
* Test of pdf method, of class Poisson.
*/
@Test
public void testPdf() {
System.out.println("pdf");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertEquals(0.0, instance.p(-1), 1E-7);
assertEquals(0.03019738, instance.p(0), 1E-7);
assertEquals(0.1056908, instance.p(1), 1E-7);
assertEquals(0.1849590, instance.p(2), 1E-7);
assertEquals(0.2157855, instance.p(3), 1E-7);
assertEquals(0.1888123, instance.p(4), 1E-7);
assertEquals(0.00229555, instance.p(10), 1E-7);
assertEquals(9.445079e-10, instance.p(20), 1E-10);
assertEquals(8.256008e-106, instance.p(100), 1E-110);
}
/**
* Test of logPdf method, of class Poisson.
*/
@Test
public void testLogPdf() {
System.out.println("logPdf");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertTrue(Double.isInfinite(instance.logp(-1)));
assertEquals(-3.5, instance.logp(0), 1E-7);
assertEquals(-2.247237, instance.logp(1), 1E-6);
assertEquals(-1.687621, instance.logp(2), 1E-6);
assertEquals(-1.533471, instance.logp(3), 1E-6);
assertEquals(-1.667002, instance.logp(4), 1E-6);
assertEquals(-6.076783, instance.logp(10), 1E-6);
assertEquals(-20.78036, instance.logp(20), 1E-5);
assertEquals(-241.9631, instance.logp(100), 1E-4);
}
/**
* Test of cdf method, of class Poisson.
*/
@Test
public void testCdf() {
System.out.println("cdf");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertEquals(0, instance.cdf(-1), 1E-7);
assertEquals(0.03019738, instance.cdf(0), 1E-7);
assertEquals(0.1358882, instance.cdf(1), 1E-7);
assertEquals(0.3208472, instance.cdf(2), 1E-7);
assertEquals(0.5366327, instance.cdf(3), 1E-7);
assertEquals(0.725445, instance.cdf(4), 1E-6);
assertEquals(0.9989806, instance.cdf(10), 1E-6);
assertEquals(0.999999, instance.cdf(15), 1E-6);
assertEquals(1.000000, instance.cdf(20), 1E-6);
}
/**
* Test of quantile method, of class Poisson.
*/
@Test
public void testQuantile() {
System.out.println("quantile");
PoissonDistribution instance = new PoissonDistribution(3.5);
instance.rand();
assertEquals(0, instance.quantile(0.01), 1E-7);
assertEquals(1, instance.quantile(0.1), 1E-7);
assertEquals(2, instance.quantile(0.2), 1E-7);
assertEquals(2, instance.quantile(0.3), 1E-7);
assertEquals(3, instance.quantile(0.4), 1E-6);
assertEquals(3, instance.quantile(0.5), 1E-6);
assertEquals(6, instance.quantile(0.9), 1E-6);
assertEquals(8, instance.quantile(0.99), 1E-6);
}
}