/* ===========================================================
* 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.]
*
* -----------------------------
* MeanAndStandardDeviation.java
* -----------------------------
* (C) Copyright 2003-2007, 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</code> permitted).
* @param standardDeviation the standard deviation (<code>null</code>
* 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</code>, this method will return <code>Double.NaN</code>.
*
* @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</code>, this method will return
* <code>Double.NaN</code>.
*
* @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</code> 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 + "]";
}
}
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