001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2008, 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 2001-2008, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * Changes
036     * -------
037     * 31-Oct-2001 : Initial version (DG);
038     * 05-May-2004 : Added getZ() method;
039     * 15-Jul-2004 : Switched getZ() and getZValue() methods (DG);
040     * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.xy (DG);
041     *
042     */
043    
044    package org.jfree.data.xy;
045    
046    /**
047     * The interface through which JFreeChart obtains data in the form of (x, y, z)
048     * items - used for XY and XYZ plots.
049     */
050    public interface XYZDataset extends XYDataset {
051    
052        /**
053         * Returns the z-value for the specified series and item.
054         *
055         * @param series  the series index (zero-based).
056         * @param item  the item index (zero-based).
057         *
058         * @return The z-value (possibly <code>null</code>).
059         */
060        public Number getZ(int series, int item);
061    
062        /**
063         * Returns the z-value (as a double primitive) for an item within a series.
064         *
065         * @param series  the series (zero-based index).
066         * @param item  the item (zero-based index).
067         *
068         * @return The z-value.
069         */
070        public double getZValue(int series, int item);
071    
072    }