/*
 * 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.math.stat.descriptive;

import org.apache.commons.math.stat.descriptive.moment.FourthMoment;
import org.apache.commons.math.stat.descriptive.moment.Kurtosis;
import org.apache.commons.math.stat.descriptive.moment.Mean;
import org.apache.commons.math.stat.descriptive.moment.Skewness;
import org.apache.commons.math.stat.descriptive.moment.Variance;

import junit.framework.TestCase;

/**
 * @version $Revision$ $Date$
 */
public class InteractionTest extends TestCase {

	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 };

	public InteractionTest(String name) {
		super(name);
	}

	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]);
		}

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

	}

}
