001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * --------------------
028 * VectorXYDataset.java
029 * --------------------
030 * (C) Copyright 2007-present, by David Gilbert and Contributors.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.data.xy;
038
039/**
040 * An extension of the {@link XYDataset} interface that allows a vector to be
041 * defined at a specific (x, y) location.
042 */
043public interface VectorXYDataset extends XYDataset {
044
045    /**
046     * Returns the x-component of the vector for an item in a series.
047     *
048     * @param series  the series index.
049     * @param item  the item index.
050     *
051     * @return The x-component of the vector.
052     */
053    double getVectorXValue(int series, int item);
054
055    /**
056     * Returns the y-component of the vector for an item in a series.
057     *
058     * @param series  the series index.
059     * @param item  the item index.
060     *
061     * @return The y-component of the vector.
062     */
063    double getVectorYValue(int series, int item);
064
065    /**
066     * Returns the vector for an item in a series.  Depending on the particular
067     * dataset implementation, this may involve creating a new {@link Vector}
068     * instance --- if you are just interested in the x and y components,
069     * use the {@link #getVectorXValue(int, int)} and
070     * {@link #getVectorYValue(int, int)} methods instead.
071     *
072     * @param series  the series index.
073     * @param item  the item index.
074     *
075     * @return The vector (possibly {@code null}).
076     */
077    Vector getVector(int series, int item);
078
079}