    001/* ===========================================================
    002 * JFreeChart : a free chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C) Copyright 2000-2011, 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 * [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 * HeatMapDataset.java
    029 * -------------------
    030 * (C) Copyright 2009, by Object Refinery Limited.
    031 *
    032 * Original Author:  David Gilbert (for Object Refinery Limited);
    033 * Contributor(s):   -;
    034 *
    035 * Changes:
    036 * --------
    037 * 28-Jan-2009 : Version 1 (DG);
    038 *
    039 */
    040
    041package org.jfree.data.general;
    042
    043/**
    044 * A dataset that represents a rectangular grid of (x, y, z) values.  The x
    045 * and y values appear at regular intervals in the dataset, while the z-values
    046 * can take any value (including <code>null</code> for unknown values).
    047 *
    048 * @since 1.0.13
    049 */
    050public interface HeatMapDataset {
    051
    052    /**
    053     * Returns the number of x values across the width of the dataset.  The
    054     * values are evenly spaced between {@link #getMinimumXValue()} and
    055     * {@link #getMaximumXValue()}.
    056     *
    057     * @return The number of x-values (always > 0).
    058     */
    059    public int getXSampleCount();
    060
    061    /**
    062     * Returns the number of y values (or samples) for the dataset.  The
    063     * values are evenly spaced between {@link #getMinimumYValue()} and
    064     * {@link #getMaximumYValue()}.
    065     *
    066     * @return The number of y-values (always > 0).
    067     */
    068    public int getYSampleCount();
    069
    070    /**
    071     * Returns the lowest x-value represented in this dataset.  A requirement
    072     * of this interface is that this method must never return infinite or
    073     * Double.NAN values.
    074     *
    075     * @return The lowest x-value represented in this dataset.
    076     */
    077    public double getMinimumXValue();
    078
    079    /**
    080     * Returns the highest x-value represented in this dataset.  A requirement
    081     * of this interface is that this method must never return infinite or
    082     * Double.NAN values.
    083     *
    084     * @return The highest x-value represented in this dataset.
    085     */
    086    public double getMaximumXValue();
    087
    088    /**
    089     * Returns the lowest y-value represented in this dataset.  A requirement
    090     * of this interface is that this method must never return infinite or
    091     * Double.NAN values.
    092     *
    093     * @return The lowest y-value represented in this dataset.
    094     */
    095    public double getMinimumYValue();
    096
    097    /**
    098     * Returns the highest y-value represented in this dataset.  A requirement
    099     * of this interface is that this method must never return infinite or
    100     * Double.NAN values.
    101     *
    102     * @return The highest y-value represented in this dataset.
    103     */
    104    public double getMaximumYValue();
    105
    106    /**
    107     * A convenience method that returns the x-value for the given index.
    108     *
    109     * @param xIndex  the xIndex.
    110     *
    111     * @return The x-value.
    112     */
    113    public double getXValue(int xIndex);
    114
    115    /**
    116     * A convenience method that returns the y-value for the given index.
    117     *
    118     * @param yIndex  the yIndex.
    119     *
    120     * @return The y-value.
    121     */
    122    public double getYValue(int yIndex);
    123
    124    /**
    125     * Returns the z-value at the specified sample position in the dataset.
    126     * For a missing or unknown value, this method should return Double.NAN.
    127     *
    128     * @param xIndex  the position of the x sample in the dataset.
    129     * @param yIndex  the position of the y sample in the dataset.
    130     *
    131     * @return The z-value.
    132     */
    133    public double getZValue(int xIndex, int yIndex);
    134
    135    /**
    136     * Returns the z-value at the specified sample position in the dataset.
    137     * This method can return <code>null</code> to indicate a missing/unknown
    138     * value.
    139     * <br><br>
    140     * Bear in mind that the class implementing this interface may
    141     * store its data using primitives rather than objects, so calling this
    142     * method may require a new <code>Number</code> object to be allocated...
    143     * for this reason, it is generally preferable to use the
    144     * {@link #getZValue(int, int)} method unless you *know* that the dataset
    145     * implementation stores the z-values using objects.
    146     *
    147     * @param xIndex  the position of the x sample in the dataset.
    148     * @param yIndex  the position of the y sample in the dataset.
    149     *
    150     * @return The z-value (possibly <code>null</code>).
    151     */
    152    public Number getZ(int xIndex, int yIndex);
    153
    154}