1   /*
2    * Copyright 2003-2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.math.stat.descriptive.summary;
17  
18  import junit.framework.Test;
19  import junit.framework.TestSuite;
20  
21  import org.apache.commons.math.stat.descriptive.StorelessUnivariateStatisticAbstractTest;
22  import org.apache.commons.math.stat.descriptive.UnivariateStatistic;
23  
24  /**
25   * Test cases for the {@link SumOfSquares} class.
26   * 
27   * @version $Revision: 155427 $ $Date: 2005-02-26 06:11:52 -0700 (Sat, 26 Feb 2005) $
28   */
29  public class SumSqTest extends StorelessUnivariateStatisticAbstractTest{
30  
31      protected SumOfSquares stat;
32      
33      /**
34       * @param name
35       */
36      public SumSqTest(String name) {
37          super(name);
38      }
39  
40      public static Test suite() {
41          TestSuite suite = new TestSuite(SumSqTest.class);
42          suite.setName("SumSq Tests");
43          return suite;
44      }
45      
46      /* (non-Javadoc)
47       * @see org.apache.commons.math.stat.descriptive.UnivariateStatisticAbstractTest#getUnivariateStatistic()
48       */
49      public UnivariateStatistic getUnivariateStatistic() {
50          return new SumOfSquares();
51      }
52  
53      /* (non-Javadoc)
54       * @see org.apache.commons.math.stat.descriptive.UnivariateStatisticAbstractTest#expectedValue()
55       */
56      public double expectedValue() {
57          return this.sumSq;
58      }
59      
60      public void testSpecialValues() {
61          SumOfSquares sumSq = new SumOfSquares();
62          assertTrue(Double.isNaN(sumSq.getResult()));
63          sumSq.increment(2d);
64          assertEquals(4d, sumSq.getResult(), 0);
65          sumSq.increment(Double.POSITIVE_INFINITY);
66          assertEquals(Double.POSITIVE_INFINITY, sumSq.getResult(), 0);
67          sumSq.increment(Double.NEGATIVE_INFINITY);
68          assertEquals(Double.POSITIVE_INFINITY, sumSq.getResult(), 0);
69          sumSq.increment(Double.NaN);
70          assertTrue(Double.isNaN(sumSq.getResult())); 
71          sumSq.increment(1);
72          assertTrue(Double.isNaN(sumSq.getResult())); 
73      }
74  
75  }