logaxis.java

jfreechart-1.0.12.zip 可以用来作图

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, 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.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * ------------
 * LogAxis.java
 * ------------
 * (C) Copyright 2006-2008, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Andrew Mickish (patch 1868745);
 *                   Peter Kolb (patch 1934255);
 *
 * Changes
 * -------
 * 24-Aug-2006 : Version 1 (DG);
 * 22-Mar-2007 : Use defaultAutoArrange attribute (DG);
 * 02-Aug-2007 : Fixed zooming bug, added support for margins (DG);
 * 14-Feb-2008 : Changed default minorTickCount to 9 - see bug report
 *               1892419 (DG);
 * 15-Feb-2008 : Applied a variation of patch 1868745 by Andrew Mickish to
 *               fix a labelling bug when the axis appears at the top or
 *               right of the chart (DG);
 * 19-Mar-2008 : Applied patch 1902418 by Andrew Mickish to fix bug in tick
 *               labels for vertical axis (DG);
 * 26-Mar-2008 : Changed createTickLabel() method from private to protected -
 *               see patch 1918209 by Andrew Mickish (DG);
 * 25-Sep-2008 : Moved minor tick fields up to superclass, see patch 1934255 
 *               by Peter Kolb (DG);
 *
 */

package org.jfree.chart.axis;

import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;
import java.awt.geom.Rectangle2D;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

import org.jfree.chart.event.AxisChangeEvent;
import org.jfree.chart.plot.Plot;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.chart.plot.ValueAxisPlot;
import org.jfree.data.Range;
import org.jfree.ui.RectangleEdge;
import org.jfree.ui.RectangleInsets;
import org.jfree.ui.TextAnchor;

/**
 * A numerical axis that uses a logarithmic scale.  The class is an
 * alternative to the {@link LogarithmicAxis} class.
 *
 * @since 1.0.7
 */
public class LogAxis extends ValueAxis {

    /** The logarithm base. */
    private double base = 10.0;

    /** The logarithm of the base value - cached for performance. */
    private double baseLog = Math.log(10.0);

    /**  The smallest value permitted on the axis. */
    private double smallestValue = 1E-100;

    /** The current tick unit. */
    private NumberTickUnit tickUnit;

    /** The override number format. */
    private NumberFormat numberFormatOverride;

    /**
     * Creates a new <code>LogAxis</code> with no label.
     */
    public LogAxis() {
        this(null);
    }

    /**
     * Creates a new <code>LogAxis</code> with the given label.
     *
     * @param label  the axis label (<code>null</code> permitted).
     */
    public LogAxis(String label) {
        super(label, createLogTickUnits(Locale.getDefault()));
        setDefaultAutoRange(new Range(0.01, 1.0));
        this.tickUnit = new NumberTickUnit(1.0, new DecimalFormat("0.#"));
        setMinorTickCount(9);
    }

    /**
     * Returns the base for the logarithm calculation.
     *
     * @return The base for the logarithm calculation.
     *
     * @see #setBase(double)
     */
    public double getBase() {
        return this.base;
    }

    /**
     * Sets the base for the logarithm calculation and sends an
     * {@link AxisChangeEvent} to all registered listeners.
     *
     * @param base  the base value (must be > 1.0).
     *
     * @see #getBase()
     */
    public void setBase(double base) {
        if (base <= 1.0) {
            throw new IllegalArgumentException("Requires 'base' > 1.0.");
        }
        this.base = base;
        this.baseLog = Math.log(base);
        notifyListeners(new AxisChangeEvent(this));
    }

    /**
     * Returns the smallest value represented by the axis.
     *
     * @return The smallest value represented by the axis.
     *
     * @see #setSmallestValue(double)
     */
    public double getSmallestValue() {
        return this.smallestValue;
    }

    /**
     * Sets the smallest value represented by the axis and sends an
     * {@link AxisChangeEvent} to all registered listeners.
     *
     * @param value  the value.
     *
     * @see #getSmallestValue()
     */
    public void setSmallestValue(double value) {
        if (value <= 0.0) {
            throw new IllegalArgumentException("Requires 'value' > 0.0.");
        }
        this.smallestValue = value;
        notifyListeners(new AxisChangeEvent(this));
    }

    /**
     * Returns the current tick unit.
     *
     * @return The current tick unit.
     *
     * @see #setTickUnit(NumberTickUnit)
     */
    public NumberTickUnit getTickUnit() {
        return this.tickUnit;
    }

    /**
     * Sets the tick unit for the axis and sends an {@link AxisChangeEvent} to
     * all registered listeners.  A side effect of calling this method is that
     * the "auto-select" feature for tick units is switched off (you can
     * restore it using the {@link ValueAxis#setAutoTickUnitSelection(boolean)}
     * method).
     *
     * @param unit  the new tick unit (<code>null</code> not permitted).
     *
     * @see #getTickUnit()
     */
    public void setTickUnit(NumberTickUnit unit) {
        // defer argument checking...
        setTickUnit(unit, true, true);
    }

    /**
     * Sets the tick unit for the axis and, if requested, sends an
     * {@link AxisChangeEvent} to all registered listeners.  In addition, an
     * option is provided to turn off the "auto-select" feature for tick units
     * (you can restore it using the
     * {@link ValueAxis#setAutoTickUnitSelection(boolean)} method).
     *
     * @param unit  the new tick unit (<code>null</code> not permitted).
     * @param notify  notify listeners?
     * @param turnOffAutoSelect  turn off the auto-tick selection?
     *
     * @see #getTickUnit()
     */
    public void setTickUnit(NumberTickUnit unit, boolean notify,
                            boolean turnOffAutoSelect) {

        if (unit == null) {
            throw new IllegalArgumentException("Null 'unit' argument.");
        }
        this.tickUnit = unit;
        if (turnOffAutoSelect) {
            setAutoTickUnitSelection(false, false);
        }
        if (notify) {
            notifyListeners(new AxisChangeEvent(this));
        }

    }

    /**
     * Returns the number format override.  If this is non-null, then it will
     * be used to format the numbers on the axis.
     *
     * @return The number formatter (possibly <code>null</code>).
     *
     * @see #setNumberFormatOverride(NumberFormat)
     */
    public NumberFormat getNumberFormatOverride() {
        return this.numberFormatOverride;
    }

    /**
     * Sets the number format override.  If this is non-null, then it will be
     * used to format the numbers on the axis.
     *
     * @param formatter  the number formatter (<code>null</code> permitted).
     *
     * @see #getNumberFormatOverride()
     */
    public void setNumberFormatOverride(NumberFormat formatter) {
        this.numberFormatOverride = formatter;
        notifyListeners(new AxisChangeEvent(this));
    }

    /**
     * Calculates the log of the given value, using the current base.
     *
     * @param value  the value.
     *
     * @return The log of the given value.
     *
     * @see #calculateValue(double)
     * @see #getBase()
     */
    public double calculateLog(double value) {
        return Math.log(value) / this.baseLog;
    }

    /**
     * Calculates the value from a given log.
     *
     * @param log  the log value (must be > 0.0).
     *
     * @return The value with the given log.
     *
     * @see #calculateLog(double)
     * @see #getBase()
     */
    public double calculateValue(double log) {
        return Math.pow(this.base, log);
    }

    /**
     * Converts a Java2D coordinate to an axis value, assuming that the
     * axis covers the specified <code>edge</code> of the <code>area</code>.
     *
     * @param java2DValue  the Java2D coordinate.
     * @param area  the area.
     * @param edge  the edge that the axis belongs to.
     *
     * @return A value along the axis scale.
     */
    public double java2DToValue(double java2DValue, Rectangle2D area,
            RectangleEdge edge) {

        Range range = getRange();
        double axisMin = calculateLog(range.getLowerBound());
        double axisMax = calculateLog(range.getUpperBound());

        double min = 0.0;
        double max = 0.0;
        if (RectangleEdge.isTopOrBottom(edge)) {
            min = area.getX();
            max = area.getMaxX();
        }
        else if (RectangleEdge.isLeftOrRight(edge)) {