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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.math3.stat.descriptive.rank;
18  
19  import org.apache.commons.math3.stat.descriptive.StorelessUnivariateStatisticAbstractTest;
20  import org.apache.commons.math3.stat.descriptive.UnivariateStatistic;
21  import org.junit.Assert;
22  import org.junit.Test;
23  
24  /**
25   * Test cases for the {@link UnivariateStatistic} class.
26   */
27  public class MaxTest extends StorelessUnivariateStatisticAbstractTest {
28  
29      protected Max stat;
30  
31      /**
32       * {@inheritDoc}
33       */
34      @Override
35      public UnivariateStatistic getUnivariateStatistic() {
36          return new Max();
37      }
38  
39      /**
40       * {@inheritDoc}
41       */
42      @Override
43      public double expectedValue() {
44          return this.max;
45      }
46  
47      @Test
48      public void testSpecialValues() {
49          double[] testArray = {0d, Double.NaN, Double.NEGATIVE_INFINITY,
50                  Double.POSITIVE_INFINITY};
51          Max max = new Max();
52          Assert.assertTrue(Double.isNaN(max.getResult()));
53          max.increment(testArray[0]);
54          Assert.assertEquals(0d, max.getResult(), 0);
55          max.increment(testArray[1]);
56          Assert.assertEquals(0d, max.getResult(), 0);
57          max.increment(testArray[2]);
58          Assert.assertEquals(0d, max.getResult(), 0);
59          max.increment(testArray[3]);
60          Assert.assertEquals(Double.POSITIVE_INFINITY, max.getResult(), 0);
61          Assert.assertEquals(Double.POSITIVE_INFINITY, max.evaluate(testArray), 0);
62      }
63  
64      @Test
65      public void testNaNs() {
66          Max max = new Max();
67          double nan = Double.NaN;
68          Assert.assertEquals(3d, max.evaluate(new double[]{nan, 2d, 3d}), 0);
69          Assert.assertEquals(3d, max.evaluate(new double[]{1d, nan, 3d}), 0);
70          Assert.assertEquals(2d, max.evaluate(new double[]{1d, 2d, nan}), 0);
71          Assert.assertTrue(Double.isNaN(max.evaluate(new double[]{nan, nan, nan})));
72      }
73  
74  }