commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/stat/descriptive/moment/InteractionTest.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.math4.legacy.stat.descriptive.moment;

import org.junit.Assert;
import org.junit.Test;


/**
 */
public class InteractionTest {

    protected double mean = 12.40454545454550;
    protected double var = 10.00235930735930;
    protected double skew = 1.437423729196190;
    protected double kurt = 2.377191264804700;

    protected double tolerance = 10E-12;

    protected double[] testArray =
        {
            12.5,
            12,
            11.8,
            14.2,
            14.9,
            14.5,
            21,
            8.2,
            10.3,
            11.3,
            14.1,
            9.9,
            12.2,
            12,
            12.1,
            11,
            19.8,
            11,
            10,
            8.8,
            9,
            12.3 };

    @Test
    public void testInteraction() {

        FourthMoment m4 = new FourthMoment();
        Mean m = new Mean(m4);
        Variance v = new Variance(m4);
        Skewness s= new Skewness(m4);
        Kurtosis k = new Kurtosis(m4);

        for (int i = 0; i < testArray.length; i++){
            m4.increment(testArray[i]);
        }

        Assert.assertEquals(mean,m.getResult(),tolerance);
        Assert.assertEquals(var,v.getResult(),tolerance);
        Assert.assertEquals(skew ,s.getResult(),tolerance);
        Assert.assertEquals(kurt,k.getResult(),tolerance);

    }

}