    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;
    17
    18  import org.apache.commons.math.stat.descriptive.moment.FourthMoment;
    19  import org.apache.commons.math.stat.descriptive.moment.Kurtosis;
    20  import org.apache.commons.math.stat.descriptive.moment.Mean;
    21  import org.apache.commons.math.stat.descriptive.moment.Skewness;
    22  import org.apache.commons.math.stat.descriptive.moment.Variance;
    23
    24  import junit.framework.TestCase;
    25
    26  /***
    27   * @version $Revision: 1.1 $ $Date: 2004/10/08 05:08:19 $
    28   */
    29  public class InteractionTest extends TestCase {
    30
    31      protected double mean = 12.40454545454550;
    32      protected double var = 10.00235930735930;
    33      protected double skew = 1.437423729196190;
    34      protected double kurt = 2.377191264804700;
    35
    36      protected double tolerance = 10E-12;
    37
    38      protected double[] testArray =
    39          {
    40              12.5,
    41              12,
    42              11.8,
    43              14.2,
    44              14.9,
    45              14.5,
    46              21,
    47              8.2,
    48              10.3,
    49              11.3,
    50              14.1,
    51              9.9,
    52              12.2,
    53              12,
    54              12.1,
    55              11,
    56              19.8,
    57              11,
    58              10,
    59              8.8,
    60              9,
    61              12.3 };
    62
    63      public InteractionTest(String name) {
    64          super(name);
    65      }
    66
    67
    68      public void testInteraction() {
    69
    70          FourthMoment m4 = new FourthMoment();
    71          Mean m = new Mean(m4);
    72          Variance v = new Variance(m4);
    73          Skewness s= new Skewness(m4);
    74          Kurtosis k = new Kurtosis(m4);
    75
    76          for (int i = 0; i < testArray.length; i++){
    77              m4.increment(testArray[i]);
    78          }
    79
    80          assertEquals(mean,m.getResult(),tolerance);
    81          assertEquals(var,v.getResult(),tolerance);
    82          assertEquals(skew ,s.getResult(),tolerance);
    83          assertEquals(kurt,k.getResult(),tolerance);
    84
    85      }
    86
    87  }