statisticstests.java

用于制作报表的中间件控件,纯java编写,还附带有数据库操作的源代码

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2007, 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.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * --------------------
 * StatisticsTests.java
 * --------------------
 * (C) Copyright 2004-2007, 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.junit;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

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

import org.jfree.data.statistics.Statistics;

/**
 * Tests for the {@link Statistics} class.
 */
public class StatisticsTests extends TestCase {
    
    /**
     * Returns the tests as a test suite.
     *
     * @return The test suite.
     */
    public static Test suite() {
        return new TestSuite(StatisticsTests.class);
    }

    /**
     * Constructs a new set of tests.
     *
     * @param name  the name of the tests.
     */
    public StatisticsTests(String name) {
        super(name);
    }

    /**
     * Some checks for the calculateMean(Number[]) and 
     * calculateMean(Number[], boolean) methods.
     */
    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.
     */
    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.
     */
    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;
        }