001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     * 
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     * 
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.math.special;
018    
019    import org.apache.commons.math.MathException;
020    import org.apache.commons.math.TestUtils;
021    
022    import junit.framework.TestCase;
023    
024    /**
025     * @version $Revision: 670469 $ $Date: 2008-06-23 04:01:38 -0400 (Mon, 23 Jun 2008) $
026     */
027    public class BetaTest extends TestCase {
028        /**
029         * Constructor for BetaTest.
030         * @param name
031         */
032        public BetaTest(String name) {
033            super(name);
034        }
035    
036        private void testRegularizedBeta(double expected, double x, double a,
037            double b)
038        {
039            try {
040                double actual = Beta.regularizedBeta(x, a, b);
041                TestUtils.assertEquals(expected, actual, 10e-15);
042            } catch(MathException ex){
043                fail(ex.getMessage());
044            }
045        }
046    
047        private void testLogBeta(double expected, double a, double b) {
048            double actual = Beta.logBeta(a, b);
049            TestUtils.assertEquals(expected, actual, 10e-15);
050        }
051    
052        public void testRegularizedBetaNanPositivePositive() {
053            testRegularizedBeta(Double.NaN, Double.NaN, 1.0, 1.0);
054        }
055    
056        public void testRegularizedBetaPositiveNanPositive() {
057            testRegularizedBeta(Double.NaN, 0.5, Double.NaN, 1.0);
058        }
059    
060        public void testRegularizedBetaPositivePositiveNan() {
061            testRegularizedBeta(Double.NaN, 0.5, 1.0, Double.NaN);
062        }
063        
064        public void testRegularizedBetaNegativePositivePositive() {
065            testRegularizedBeta(Double.NaN, -0.5, 1.0, 2.0);
066        }
067        
068        public void testRegularizedBetaPositiveNegativePositive() {
069            testRegularizedBeta(Double.NaN, 0.5, -1.0, 2.0);
070        }
071        
072        public void testRegularizedBetaPositivePositiveNegative() {
073            testRegularizedBeta(Double.NaN, 0.5, 1.0, -2.0);
074        }
075        
076        public void testRegularizedBetaZeroPositivePositive() {
077            testRegularizedBeta(0.0, 0.0, 1.0, 2.0);
078        }
079        
080        public void testRegularizedBetaPositiveZeroPositive() {
081            testRegularizedBeta(Double.NaN, 0.5, 0.0, 2.0);
082        }
083        
084        public void testRegularizedBetaPositivePositiveZero() {
085            testRegularizedBeta(Double.NaN, 0.5, 1.0, 0.0);
086        }
087        
088        public void testRegularizedBetaPositivePositivePositive() {
089            testRegularizedBeta(0.75, 0.5, 1.0, 2.0);
090        }
091        
092        public void testLogBetaNanPositive() {
093            testLogBeta(Double.NaN, Double.NaN, 2.0);
094        }
095        
096        public void testLogBetaPositiveNan() {
097            testLogBeta(Double.NaN, 1.0, Double.NaN);
098        }
099        
100        public void testLogBetaNegativePositive() {
101            testLogBeta(Double.NaN, -1.0, 2.0);
102        }
103        
104        public void testLogBetaPositiveNegative() {
105            testLogBeta(Double.NaN, 1.0, -2.0);
106        }
107        
108        public void testLogBetaZeroPositive() {
109            testLogBeta(Double.NaN, 0.0, 2.0);
110        }
111        
112        public void testLogBetaPositiveZero() {
113            testLogBeta(Double.NaN, 1.0, 0.0);
114        }
115        
116        public void testLogBetaPositivePositive() {
117            testLogBeta(-0.693147180559945, 1.0, 2.0);
118        }
119    }