gt:         data2[0] = new Double(1);
context: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2016, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * -------------------
   * StatisticsTest.java
   * -------------------
   * (C) Copyright 2004-2016, by Object Refinery Limited and Contributors.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 25-Mar-2004 : Version 1 (DG);
   * 04-Oct-2004 : Eliminated NumberUtils usage (DG);
   *
   */
  
  package org.jfree.data.statistics;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import org.junit.Test;
  
  /**
   * Tests for the {@link Statistics} class.
   */
  public class StatisticsTest {
  
      /**
       * Some checks for the calculateMean(Number[]) and
       * calculateMean(Number[], boolean) methods.
       */
      @Test
      public void testCalculateMean_Array() {
  
          // try null array
          boolean pass = false;
          try {
              Statistics.calculateMean((Number[]) null);
          }
          catch (IllegalArgumentException e) {
              pass = true;
          }
          assertTrue(pass);
  
          pass = false;
          try {
              Statistics.calculateMean((Number[]) null, false);
          }
          catch (IllegalArgumentException e) {
              pass = true;
          }
          assertTrue(pass);
  
          // try an array containing no items
          assertTrue(Double.isNaN(Statistics.calculateMean(new Number[0])));
          assertTrue(Double.isNaN(Statistics.calculateMean(new Number[0],
                  false)));
  
          // try an array containing a single Number
          Number[] values = new Number[] {new Double(1.0)};
          assertEquals(1.0, Statistics.calculateMean(values), EPSILON);
          assertEquals(1.0, Statistics.calculateMean(values, true), EPSILON);
          assertEquals(1.0, Statistics.calculateMean(values, false), EPSILON);
  
          // try an array containing a single Number and a null
          values = new Number[] {new Double(1.0), null};
          assertTrue(Double.isNaN(Statistics.calculateMean(values)));
          assertTrue(Double.isNaN(Statistics.calculateMean(values, true)));
          assertEquals(1.0, Statistics.calculateMean(values, false), EPSILON);
  
          // try an array containing a single Number and a NaN
          values = new Number[] {new Double(1.0), new Double(Double.NaN)};
          assertTrue(Double.isNaN(Statistics.calculateMean(values)));
          assertTrue(Double.isNaN(Statistics.calculateMean(values, true)));
          assertEquals(1.0, Statistics.calculateMean(values, false), EPSILON);
      }
  
      /**
       * Some checks for the calculateMean(Collection) and
       * calculateMean(Collection, boolean) methods.
       */
      @Test
      public void testCalculateMean_Collection() {
  
          // try a null collection
          boolean pass = false;
          try {
              Statistics.calculateMean((Collection) null);
          }
          catch (IllegalArgumentException e) {
              pass = true;
          }
          assertTrue(pass);
  
          pass = false;
          try {
              Statistics.calculateMean((Collection) null, false);
          }
          catch (IllegalArgumentException e) {
              pass = true;
          }
          assertTrue(pass);
  
          // try an empty collection
          List values = new ArrayList();
          assertTrue(Double.isNaN(Statistics.calculateMean(values)));
          assertTrue(Double.isNaN(Statistics.calculateMean(values, true)));
          assertTrue(Double.isNaN(Statistics.calculateMean(values, false)));
  
          // try a collection with a single number
          values.add(new Double(9.0));
          assertEquals(9.0, Statistics.calculateMean(values), EPSILON);
          assertEquals(9.0, Statistics.calculateMean(values, true), EPSILON);
          assertEquals(9.0, Statistics.calculateMean(values, false), EPSILON);
  
          // try a collection with a single number plus a null
          values.add(null);
          assertTrue(Double.isNaN(Statistics.calculateMean(values)));
          assertTrue(Double.isNaN(Statistics.calculateMean(values, true)));
          assertEquals(9.0, Statistics.calculateMean(values, false), EPSILON);
  
          // try a collection with a single number plus a NaN
          values.clear();
          values.add(new Double(9.0));
          values.add(new Double(Double.NaN));
          assertTrue(Double.isNaN(Statistics.calculateMean(values)));
          assertTrue(Double.isNaN(Statistics.calculateMean(values, true)));
          assertEquals(9.0, Statistics.calculateMean(values, false), EPSILON);
  
          // try a collection with several numbers
          values = new ArrayList();
          values.add(new Double(9.0));
          values.add(new Double(3.0));
          values.add(new Double(2.0));
          values.add(new Double(2.0));
          double mean = Statistics.calculateMean(values);
          assertEquals(4.0, mean, EPSILON);
  
          // a Collection containing a NaN will return Double.NaN for the result
          values.add(new Double(Double.NaN));
          assertTrue(Double.isNaN(Statistics.calculateMean(values)));
      }
  
      static final double EPSILON = 0.0000000001;
  
      /**
       * Some checks for the calculateMedian(List, boolean) method.
       */
      @Test
      public void testCalculateMedian() {
  
          // check null list
          assertTrue(Double.isNaN(Statistics.calculateMedian(null, false)));
          assertTrue(Double.isNaN(Statistics.calculateMedian(null, true)));
  
          // check empty list
          List list = new ArrayList();
          assertTrue(Double.isNaN(Statistics.calculateMedian(list, false)));
          assertTrue(Double.isNaN(Statistics.calculateMedian(list, true)));
  
          // check list containing null
          list.add(null);
          boolean pass = false;
          try {
              Statistics.calculateMedian(list, false);
          }
          catch (NullPointerException e) {
              pass = true;
          }
          assertTrue(pass);
  
          pass = false;
          try {
              Statistics.calculateMedian(list, true);
          }
          catch (NullPointerException e) {
              pass = true;
          }
          assertTrue(pass);
  
          // check a list containing a non-Number object
          list.clear();
          list.add("Not a number");
          pass = false;
          try {
              Statistics.calculateMedian(list, false);
          }
          catch (ClassCastException e) {
              pass = true;
          }
          assertTrue(pass);
  
          pass = false;
          try {
              Statistics.calculateMedian(list, true);
          }
          catch (ClassCastException e) {
              pass = true;
          }
          assertTrue(pass);
  
      }
  
      /**
       * A test for the calculateMedian() method.
       */
      @Test
      public void testCalculateMedian1() {
          List values = new ArrayList();
          values.add(new Double(1.0));
          double median = Statistics.calculateMedian(values);
          assertEquals(1.0, median, 0.0000001);
      }
  
      /**
       * A test for the calculateMedian() method.
       */
      @Test
      public void testCalculateMedian2() {
          List values = new ArrayList();
          values.add(new Double(2.0));
          values.add(new Double(1.0));
          double median = Statistics.calculateMedian(values);
          assertEquals(1.5, median, 0.0000001);
      }
  
      /**
       * A test for the calculateMedian() method.
       */
      @Test
      public void testCalculateMedian3() {
          List values = new ArrayList();
          values.add(new Double(1.0));
          values.add(new Double(2.0));
          values.add(new Double(3.0));
          values.add(new Double(6.0));
          values.add(new Double(5.0));
          values.add(new Double(4.0));
          double median = Statistics.calculateMedian(values);
          assertEquals(3.5, median, 0.0000001);
      }
  
      /**
       * A test for the calculateMedian() method.
       */
      @Test
      public void testCalculateMedian4() {
          List values = new ArrayList();
          values.add(new Double(7.0));
          values.add(new Double(2.0));
          values.add(new Double(3.0));
          values.add(new Double(5.0));
          values.add(new Double(4.0));
          values.add(new Double(6.0));
          values.add(new Double(1.0));
          double median = Statistics.calculateMedian(values);
          assertEquals(4.0, median, 0.0000001);
      }
  
      /**
       * A test using some real data that caused a problem at one point.
       */
      @Test
      public void testCalculateMedian5() {
          List values = new ArrayList();
          values.add(new Double(11.228692993861783));
          values.add(new Double(11.30823353859889));
          values.add(new Double(11.75312904769314));
          values.add(new Double(11.825102897465314));
          values.add(new Double(10.184252778401783));
          values.add(new Double(12.207951828057766));
          values.add(new Double(10.68841994040566));
          values.add(new Double(12.099522004479438));
          values.add(new Double(11.508874945056881));
          values.add(new Double(12.052517729558513));
          values.add(new Double(12.401481645578734));
          values.add(new Double(12.185377793028543));
          values.add(new Double(10.666372951930315));
          values.add(new Double(11.680978041499548));
          values.add(new Double(11.06528277406718));
          values.add(new Double(11.36876492904596));
          values.add(new Double(11.927565516175939));
          values.add(new Double(11.39307785978655));
          values.add(new Double(11.989603679523857));
          values.add(new Double(12.009834360354864));
          values.add(new Double(10.653351822461559));
          values.add(new Double(11.851776254376754));
          values.add(new Double(11.045441544755946));
          values.add(new Double(11.993674040560624));
          values.add(new Double(12.898219965238944));
          values.add(new Double(11.97095782819647));
          values.add(new Double(11.73234406745488));
          values.add(new Double(11.649006017243991));
          values.add(new Double(12.20549704915365));
          values.add(new Double(11.799723639384919));
          values.add(new Double(11.896208658005628));
          values.add(new Double(12.164149111823424));
          values.add(new Double(12.042795103513766));
          values.add(new Double(12.114839532596426));
          values.add(new Double(12.166609097075824));
          values.add(new Double(12.183017546225935));
          values.add(new Double(11.622009125845342));
          values.add(new Double(11.289365786738633));
          values.add(new Double(12.462984323671568));
          values.add(new Double(11.573494921030598));
          values.add(new Double(10.862867940485804));
          values.add(new Double(12.018186939664872));
          values.add(new Double(10.418046849313018));
          values.add(new Double(11.326344465881341));
          double median = Statistics.calculateMedian(values, true);
          assertEquals(11.812413268425116, median, 0.000001);
          Collections.sort(values);
          double median2 = Statistics.calculateMedian(values, false);
          assertEquals(11.812413268425116, median2, 0.000001);
      }
  
      /**
       * A test for the calculateMedian() method.
       */
      @Test
      public void testCalculateMedian6() {
          List values = new ArrayList();
          values.add(new Double(7.0));
          values.add(new Double(2.0));
          values.add(new Double(3.0));
          values.add(new Double(5.0));
          values.add(new Double(4.0));
          values.add(new Double(6.0));
          values.add(new Double(1.0));
          double median = Statistics.calculateMedian(values, 0, 2);
          assertEquals(3.0, median, 0.0000001);
      }
  
      /**
       * A simple test for the correlation calculation.
       */
      @Test
      public void testCorrelation1() {
          Number[] data1 = new Number[3];
          data1[0] = new Double(1);
          data1[1] = new Double(2);
          data1[2] = new Double(3);
          Number[] data2 = new Number[3];
  