jfreechart example source code file (MeanAndStandardDeviation.java)

This example jfreechart source code file (MeanAndStandardDeviation.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jfreechart tags/keywords

double, double, io, meanandstandarddeviation, meanandstandarddeviation, number, number, serializable, serializable, string

The jfreechart MeanAndStandardDeviation.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, 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.]
 *
 * -----------------------------
 * MeanAndStandardDeviation.java
 * -----------------------------
 * (C) Copyright 2003-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes:
 * --------
 * 05-Feb-2002 : Version 1 (DG);
 * 05-Feb-2005 : Added equals() method and implemented Serializable (DG);
 * 02-Oct-2007 : Added getMeanValue() and getStandardDeviationValue() methods
 *               for convenience, and toString() method for debugging (DG);
 *
 */

package org.jfree.data.statistics;

import java.io.Serializable;

import org.jfree.util.ObjectUtilities;

/**
 * A simple data structure that holds a mean value and a standard deviation
 * value.  This is used in the
 * {@link org.jfree.data.statistics.DefaultStatisticalCategoryDataset} class.
 */
public class MeanAndStandardDeviation implements Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 7413468697315721515L;

    /** The mean. */
    private Number mean;

    /** The standard deviation. */
    private Number standardDeviation;

    /**
     * Creates a new mean and standard deviation record.
     *
     * @param mean  the mean.
     * @param standardDeviation  the standard deviation.
     */
    public MeanAndStandardDeviation(double mean, double standardDeviation) {
        this(new Double(mean), new Double(standardDeviation));
    }

    /**
     * Creates a new mean and standard deviation record.
     *
     * @param mean  the mean (<code>null permitted).
     * @param standardDeviation  the standard deviation (<code>null
     *                           permitted.
     */
    public MeanAndStandardDeviation(Number mean, Number standardDeviation) {
        this.mean = mean;
        this.standardDeviation = standardDeviation;
    }

    /**
     * Returns the mean.
     *
     * @return The mean.
     */
    public Number getMean() {
        return this.mean;
    }

    /**
     * Returns the mean as a double primitive.  If the underlying mean is
     * <code>null, this method will return Double.NaN.
     *
     * @return The mean.
     *
     * @see #getMean()
     *
     * @since 1.0.7
     */
    public double getMeanValue() {
        double result = Double.NaN;
        if (this.mean != null) {
            result = this.mean.doubleValue();
        }
        return result;
    }

    /**
     * Returns the standard deviation.
     *
     * @return The standard deviation.
     */
    public Number getStandardDeviation() {
        return this.standardDeviation;
    }

    /**
     * Returns the standard deviation as a double primitive.  If the underlying
     * standard deviation is <code>null, this method will return
     * <code>Double.NaN.
     *
     * @return The standard deviation.
     *
     * @since 1.0.7
     */
    public double getStandardDeviationValue() {
        double result = Double.NaN;
        if (this.standardDeviation != null) {
            result = this.standardDeviation.doubleValue();
        }
        return result;
    }

    /**
     * Tests this instance for equality with an arbitrary object.
     *
     * @param obj  the object (<code>null permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof MeanAndStandardDeviation)) {
            return false;
        }
        MeanAndStandardDeviation that = (MeanAndStandardDeviation) obj;
        if (!ObjectUtilities.equal(this.mean, that.mean)) {
            return false;
        }
        if (!ObjectUtilities.equal(
            this.standardDeviation, that.standardDeviation)
        ) {
            return false;
        }
        return true;
    }

    /**
     * Returns a string representing this instance.
     *
     * @return A string.
     *
     * @since 1.0.7
     */
    public String toString() {
        return "[" + this.mean + ", " + this.standardDeviation + "]";
    }

}