1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    * 
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.math.stat.descriptive.summary;
18  
19  import junit.framework.Test;
20  import junit.framework.TestSuite;
21  
22  import org.apache.commons.math.stat.descriptive.StorelessUnivariateStatisticAbstractTest;
23  import org.apache.commons.math.stat.descriptive.UnivariateStatistic;
24  
25  /**
26   * Test cases for the {@link SumOfSquares} class.
27   * 
28   * @version $Revision: 762087 $ $Date: 2009-04-05 10:20:18 -0400 (Sun, 05 Apr 2009) $
29   */
30  public class SumSqTest extends StorelessUnivariateStatisticAbstractTest{
31  
32      protected SumOfSquares stat;
33      
34      /**
35       * @param name
36       */
37      public SumSqTest(String name) {
38          super(name);
39      }
40  
41      public static Test suite() {
42          TestSuite suite = new TestSuite(SumSqTest.class);
43          suite.setName("SumSq Tests");
44          return suite;
45      }
46      
47      /**
48       * {@inheritDoc}
49       */
50      @Override
51      public UnivariateStatistic getUnivariateStatistic() {
52          return new SumOfSquares();
53      }
54  
55      /**
56       * {@inheritDoc}
57       */
58      @Override
59      public double expectedValue() {
60          return this.sumSq;
61      }
62      
63      public void testSpecialValues() {
64          SumOfSquares sumSq = new SumOfSquares();
65          assertTrue(Double.isNaN(sumSq.getResult()));
66          sumSq.increment(2d);
67          assertEquals(4d, sumSq.getResult(), 0);
68          sumSq.increment(Double.POSITIVE_INFINITY);
69          assertEquals(Double.POSITIVE_INFINITY, sumSq.getResult(), 0);
70          sumSq.increment(Double.NEGATIVE_INFINITY);
71          assertEquals(Double.POSITIVE_INFINITY, sumSq.getResult(), 0);
72          sumSq.increment(Double.NaN);
73          assertTrue(Double.isNaN(sumSq.getResult())); 
74          sumSq.increment(1);
75          assertTrue(Double.isNaN(sumSq.getResult())); 
76      }
77  
78  }