001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it 
010     * under the terms of the GNU Lesser General Public License as published by 
011     * the Free Software Foundation; either version 2.1 of the License, or 
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but 
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022     * USA.  
023     *
024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025     * in the United States and other countries.]
026     *
027     * ---------------
028     * XYZDataset.java
029     * ---------------
030     * (C) Copyright 2001-2004, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: XYZDataset.java,v 1.2.2.1 2005/10/25 21:36:51 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 31-Oct-2001 : Initial version (DG);
040     * 05-May-2004 : Added getZ() method;
041     * 15-Jul-2004 : Switched getZ() and getZValue() methods (DG);
042     * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.xy (DG);
043     *
044     */
045    package org.jfree.data.xy;
046    
047    
048    /**
049     * The interface through which JFreeChart obtains data in the form of (x, y, z)
050     * items - used for XY and XYZ plots.
051     */
052    public interface XYZDataset extends XYDataset {
053    
054        /**
055         * Returns the z-value for the specified series and item.
056         *
057         * @param series  the series index (zero-based).
058         * @param item  the item index (zero-based).
059         *
060         * @return The z-value (possibly <code>null</code>).
061         */
062        public Number getZ(int series, int item);
063        
064        /**
065         * Returns the z-value (as a double primitive) for an item within a series.
066         * 
067         * @param series  the series (zero-based index).
068         * @param item  the item (zero-based index).
069         * 
070         * @return The z-value.
071         */
072        public double getZValue(int series, int item);
073    
074    }