/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2005, 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.]
 *
 * -----------------------
 * AbstractXYZDataset.java
 * -----------------------
 * (C) Copyright 2004, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited).
 * Contributor(s):   -;
 *
 * $Id: AbstractXYZDataset.java,v 1.2.2.1 2005/10/25 21:36:51 mungady Exp $
 *
 * Changes
 * -------
 * 05-May-2004 : Version 1 (DG);
 * 15-Jul-2004 : Switched getZ() and getZValue() (DG);
 *
 */

package org.jfree.data.xy;


/**
 * An base class that you can use to create new implementations of the 
 * {@link XYZDataset} interface.
 */
public abstract class AbstractXYZDataset extends AbstractXYDataset 
                                         implements XYZDataset {

    /**
     * Returns the z-value (as a double primitive) for an item within a series.
     * 
     * @param series  the series (zero-based index).
     * @param item  the item (zero-based index).
     * 
     * @return The z-value.
     */
    public double getZValue(int series, int item) {
        double result = Double.NaN;
        Number z = getZ(series, item);
        if (z != null) {
            result = z.doubleValue();   
        }
        return result;   
    }

}
