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.stat.descriptive.summary;
018    
019    import junit.framework.Test;
020    import junit.framework.TestSuite;
021    
022    import org.apache.commons.math.stat.descriptive.StorelessUnivariateStatisticAbstractTest;
023    import org.apache.commons.math.stat.descriptive.UnivariateStatistic;
024    
025    /**
026     * Test cases for the {@link SumOfSquares} class.
027     * 
028     * @version $Revision: 762087 $ $Date: 2009-04-05 10:20:18 -0400 (Sun, 05 Apr 2009) $
029     */
030    public class SumSqTest extends StorelessUnivariateStatisticAbstractTest{
031    
032        protected SumOfSquares stat;
033        
034        /**
035         * @param name
036         */
037        public SumSqTest(String name) {
038            super(name);
039        }
040    
041        public static Test suite() {
042            TestSuite suite = new TestSuite(SumSqTest.class);
043            suite.setName("SumSq Tests");
044            return suite;
045        }
046        
047        /**
048         * {@inheritDoc}
049         */
050        @Override
051        public UnivariateStatistic getUnivariateStatistic() {
052            return new SumOfSquares();
053        }
054    
055        /**
056         * {@inheritDoc}
057         */
058        @Override
059        public double expectedValue() {
060            return this.sumSq;
061        }
062        
063        public void testSpecialValues() {
064            SumOfSquares sumSq = new SumOfSquares();
065            assertTrue(Double.isNaN(sumSq.getResult()));
066            sumSq.increment(2d);
067            assertEquals(4d, sumSq.getResult(), 0);
068            sumSq.increment(Double.POSITIVE_INFINITY);
069            assertEquals(Double.POSITIVE_INFINITY, sumSq.getResult(), 0);
070            sumSq.increment(Double.NEGATIVE_INFINITY);
071            assertEquals(Double.POSITIVE_INFINITY, sumSq.getResult(), 0);
072            sumSq.increment(Double.NaN);
073            assertTrue(Double.isNaN(sumSq.getResult())); 
074            sumSq.increment(1);
075            assertTrue(Double.isNaN(sumSq.getResult())); 
076        }
077    
078    }