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 UnivariateStatistic} class.
27   * @version $Revision: 762087 $ $Date: 2009-04-05 10:20:18 -0400 (Sun, 05 Apr 2009) $
28   */
29  public class SumLogTest extends StorelessUnivariateStatisticAbstractTest{
30  
31      protected SumOfLogs stat;
32      
33      /**
34       * @param name
35       */
36      public SumLogTest(String name) {
37          super(name);
38      }
39  
40      public static Test suite() {
41          TestSuite suite = new TestSuite(SumLogTest.class);
42          suite.setName("SumLog Tests");
43          return suite;
44      }
45      
46      /**
47       * {@inheritDoc}
48       */
49      @Override
50      public UnivariateStatistic getUnivariateStatistic() {        
51          return new SumOfLogs();
52      }
53  
54      /**
55       * {@inheritDoc}
56       */
57      @Override
58      public double expectedValue() {
59          return this.sumLog;
60      }
61      
62      public void testSpecialValues() {
63          SumOfLogs sum = new SumOfLogs();
64          // empty
65          assertTrue(Double.isNaN(sum.getResult()));
66          
67          // finite data
68          sum.increment(1d);
69          assertFalse(Double.isNaN(sum.getResult()));
70          
71          // add negative infinity
72          sum.increment(0d);
73          assertEquals(Double.NEGATIVE_INFINITY, sum.getResult(), 0);
74          
75          // add positive infinity -- should make NaN
76          sum.increment(Double.POSITIVE_INFINITY);
77          assertTrue(Double.isNaN(sum.getResult()));
78          
79          // clear
80          sum.clear();
81          assertTrue(Double.isNaN(sum.getResult()));
82          
83          // positive infinity by itself
84          sum.increment(Double.POSITIVE_INFINITY);
85          assertEquals(Double.POSITIVE_INFINITY, sum.getResult(), 0);
86          
87          // negative value -- should make NaN
88          sum.increment(-2d);
89          assertTrue(Double.isNaN(sum.getResult()));
90      }
91  
92  }