/*
 * 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.inference;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

import java.util.ArrayList;
import java.util.List;

/**
 * Test cases for the OneWayAnovaImpl class.
 *
 * @version $Revision$ $Date$
 */

public class OneWayAnovaTest extends TestCase {

	protected OneWayAnova testStatistic = new OneWayAnovaImpl();

	private double[] emptyArray = {};

	private double[] classA = { 93.0, 103.0, 95.0, 101.0, 91.0, 105.0, 96.0, 94.0, 101.0 };
	private double[] classB = { 99.0, 92.0, 102.0, 100.0, 102.0, 89.0 };
	private double[] classC = { 110.0, 115.0, 111.0, 117.0, 128.0, 117.0 };

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

	public static Test suite() {
		TestSuite suite = new TestSuite(OneWayAnovaTest.class);
		suite.setName("TestStatistic Tests");
		return suite;
	}

	public void testAnovaFValue() throws Exception {
		// Target comparison values computed using R version 2.6.0 (Linux
		// version)
		List<double[]> threeClasses = new ArrayList<double[]>();
		threeClasses.add(classA);
		threeClasses.add(classB);
		threeClasses.add(classC);

		assertEquals("ANOVA F-value", 24.67361709460624, testStatistic.anovaFValue(threeClasses), 1E-12);

		List<double[]> twoClasses = new ArrayList<double[]>();
		twoClasses.add(classA);
		twoClasses.add(classB);

		assertEquals("ANOVA F-value", 0.0150579150579, testStatistic.anovaFValue(twoClasses), 1E-12);

		List<double[]> emptyContents = new ArrayList<double[]>();
		emptyContents.add(emptyArray);
		emptyContents.add(classC);
		try {
			testStatistic.anovaFValue(emptyContents);
			fail("empty array for key classX, IllegalArgumentException expected");
		} catch (IllegalArgumentException ex) {
			// expected
		}

		List<double[]> tooFew = new ArrayList<double[]>();
		tooFew.add(classA);
		try {
			testStatistic.anovaFValue(tooFew);
			fail("less than two classes, IllegalArgumentException expected");
		} catch (IllegalArgumentException ex) {
			// expected
		}
	}

	public void testAnovaPValue() throws Exception {
		// Target comparison values computed using R version 2.6.0 (Linux
		// version)
		List<double[]> threeClasses = new ArrayList<double[]>();
		threeClasses.add(classA);
		threeClasses.add(classB);
		threeClasses.add(classC);

		assertEquals("ANOVA P-value", 6.959446E-06, testStatistic.anovaPValue(threeClasses), 1E-12);

		List<double[]> twoClasses = new ArrayList<double[]>();
		twoClasses.add(classA);
		twoClasses.add(classB);

		assertEquals("ANOVA P-value", 0.904212960464, testStatistic.anovaPValue(twoClasses), 1E-12);

	}

	public void testAnovaTest() throws Exception {
		// Target comparison values computed using R version 2.3.1 (Linux
		// version)
		List<double[]> threeClasses = new ArrayList<double[]>();
		threeClasses.add(classA);
		threeClasses.add(classB);
		threeClasses.add(classC);

		assertTrue("ANOVA Test P<0.01", testStatistic.anovaTest(threeClasses, 0.01));

		List<double[]> twoClasses = new ArrayList<double[]>();
		twoClasses.add(classA);
		twoClasses.add(classB);

		assertFalse("ANOVA Test P>0.01", testStatistic.anovaTest(twoClasses, 0.01));
	}

}