Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2014, 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. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * ------------------- * HeatMapDataset.java * ------------------- * (C) Copyright 2009-2014, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes: * -------- * 28-Jan-2009 : Version 1 (DG); * */ package org.jfree.data.general; /** * A dataset that represents a rectangular grid of (x, y, z) values. The x * and y values appear at regular intervals in the dataset, while the z-values * can take any value (including <code>null</code> for unknown values). * * @since 1.0.13 */ public interface HeatMapDataset { /** * Returns the number of x values across the width of the dataset. The * values are evenly spaced between {@link #getMinimumXValue()} and * {@link #getMaximumXValue()}. * * @return The number of x-values (always > 0). */ public int getXSampleCount(); /** * Returns the number of y values (or samples) for the dataset. The * values are evenly spaced between {@link #getMinimumYValue()} and * {@link #getMaximumYValue()}. * * @return The number of y-values (always > 0). */ public int getYSampleCount(); /** * Returns the lowest x-value represented in this dataset. A requirement * of this interface is that this method must never return infinite or * Double.NAN values. * * @return The lowest x-value represented in this dataset. */ public double getMinimumXValue(); /** * Returns the highest x-value represented in this dataset. A requirement * of this interface is that this method must never return infinite or * Double.NAN values. * * @return The highest x-value represented in this dataset. */ public double getMaximumXValue(); /** * Returns the lowest y-value represented in this dataset. A requirement * of this interface is that this method must never return infinite or * Double.NAN values. * * @return The lowest y-value represented in this dataset. */ public double getMinimumYValue(); /** * Returns the highest y-value represented in this dataset. A requirement * of this interface is that this method must never return infinite or * Double.NAN values. * * @return The highest y-value represented in this dataset. */ public double getMaximumYValue(); /** * A convenience method that returns the x-value for the given index. * * @param xIndex the xIndex. * * @return The x-value. */ public double getXValue(int xIndex); /** * A convenience method that returns the y-value for the given index. * * @param yIndex the yIndex. * * @return The y-value. */ public double getYValue(int yIndex); /** * Returns the z-value at the specified sample position in the dataset. * For a missing or unknown value, this method should return Double.NAN. * * @param xIndex the position of the x sample in the dataset. * @param yIndex the position of the y sample in the dataset. * * @return The z-value. */ public double getZValue(int xIndex, int yIndex); /** * Returns the z-value at the specified sample position in the dataset. * This method can return <code>null</code> to indicate a missing/unknown * value. * <br><br> * Bear in mind that the class implementing this interface may * store its data using primitives rather than objects, so calling this * method may require a new <code>Number</code> object to be allocated... * for this reason, it is generally preferable to use the * {@link #getZValue(int, int)} method unless you *know* that the dataset * implementation stores the z-values using objects. * * @param xIndex the position of the x sample in the dataset. * @param yIndex the position of the y sample in the dataset. * * @return The z-value (possibly <code>null</code>). */ public Number getZ(int xIndex, int yIndex); }