/*******************************************************************************
* 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 GammaDistributionTest {
public GammaDistributionTest() {
}
@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 GammaDistribution.
*/
@Test
public void testGammaDistribution() {
System.out.println("GammaDistribution");
GammaDistribution instance = new GammaDistribution(3, 2.1);
double[] data = new double[1000];
for (int i = 0; i < data.length; i++)
data[i] = instance.rand();
GammaDistribution est = new GammaDistribution(data);
assertEquals(0.0, (est.getScale() - 2.1) / 2.1, 0.1);
assertEquals(0.0, (est.getShape() - 3.0) / 3.0, 0.1);
}
/**
* Test of npara method, of class Gamma.
*/
@Test
public void testNpara() {
System.out.println("npara");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertEquals(2, instance.npara());
}
/**
* Test of mean method, of class Gamma.
*/
@Test
public void testMean() {
System.out.println("var");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertEquals(6.3, instance.mean(), 1E-7);
}
/**
* Test of var method, of class Gamma.
*/
@Test
public void testVar() {
System.out.println("var");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertEquals(13.23, instance.var(), 1E-7);
}
/**
* Test of sd method, of class Gamma.
*/
@Test
public void testSd() {
System.out.println("sd");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertEquals(3.637307, instance.sd(), 1E-6);
}
/**
* Test of entropy method, of class Gamma.
*/
@Test
public void testEntropy() {
System.out.println("entropy");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertEquals(2.589516, instance.entropy(), 1E-6);
}
/**
* Test of p method, of class Gamma.
*/
@Test
public void testP() {
System.out.println("p");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertEquals(0.0, instance.p(-0.1), 1E-7);
assertEquals(0.0, instance.p(0.0), 1E-7);
assertEquals(0.0005147916, instance.p(0.1), 1E-7);
assertEquals(0.03353553, instance.p(1.0), 1E-7);
assertEquals(0.08332174, instance.p(2.0), 1E-7);
assertEquals(0.1164485, instance.p(3.0), 1E-7);
assertEquals(0.1285892, instance.p(4.0), 1E-7);
assertEquals(0.04615759, instance.p(10), 1E-7);
assertEquals(0.001578462, instance.p(20), 1E-7);
assertEquals(3.036321e-05, instance.p(30), 1E-7);
}
/**
* Test of logP method, of class Gamma.
*/
@Test
public void testLogP() {
System.out.println("logP");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertTrue(Double.isInfinite(instance.logp(-0.1)));
assertTrue(Double.isInfinite(instance.logp(0.0)));
assertEquals(-3.39515, instance.logp(1.0), 1E-5);
assertEquals(-2.485046, instance.logp(2.0), 1E-6);
assertEquals(-2.150306, instance.logp(3.0), 1E-6);
assertEquals(-2.051132, instance.logp(4.0), 1E-6);
assertEquals(-3.075694, instance.logp(10.0), 1E-6);
assertEquals(-6.451304, instance.logp(20.0), 1E-6);
assertEquals(-10.40228, instance.logp(30.0), 1E-5);
}
/**
* Test of cdf method, of class Gamma.
*/
@Test
public void testCdf() {
System.out.println("cdf");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertEquals(0.0, instance.cdf(-0.1), 1E-7);
assertEquals(0.0, instance.cdf(0.0), 1E-7);
assertEquals(0.01264681, instance.cdf(1.0), 1E-7);
assertEquals(0.07175418, instance.cdf(2.0), 1E-7);
assertEquals(0.1734485, instance.cdf(3.0), 1E-7);
assertEquals(0.2975654, instance.cdf(4.0), 1E-7);
assertEquals(0.8538087, instance.cdf(10.0), 1E-7);
assertEquals(0.995916, instance.cdf(20.0), 1E-7);
assertEquals(0.9999267, instance.cdf(30.0), 1E-7);
}
/**
* Test of quantile method, of class Gamma.
*/
@Test
public void testQuantile() {
System.out.println("quantile");
GammaDistribution instance = new GammaDistribution(3, 2.1);
instance.rand();
assertEquals(0.4001201, instance.quantile(0.001), 1E-7);
assertEquals(0.9156948, instance.quantile(0.01), 1E-7);
assertEquals(2.314337, instance.quantile(0.1), 1E-6);
assertEquals(3.223593, instance.quantile(0.2), 1E-6);
assertEquals(5.615527, instance.quantile(0.5), 1E-6);
assertEquals(11.17687, instance.quantile(0.9), 1E-5);
assertEquals(17.65249, instance.quantile(0.99), 1E-5);
assertEquals(23.58063, instance.quantile(0.999), 1E-5);
}
}