Question

以下是我在JFreeChart中的面积图。面积图从0开始并上升到第一个值5或1.在y轴上400之后，它又回落到零。我希望它从5或1开始，而不是在400之后回落到0。

Area Chart http://imageshack.com/a/img837/6572/2ab0.jpg

以下是代码。如何修复它以避免零？

package com.ebay.aerohc.benchmark;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.CategoryLabelPositions;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.title.TextTitle;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.general.DatasetUtilities;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RectangleEdge;
import org.jfree.ui.RefineryUtilities;
import org.jfree.ui.VerticalAlignment;
import org.jfree.util.Log;
import org.jfree.util.PrintStreamLogTarget;

/**
 * A simple demonstration application showing how to create an area chart using data from a
 * {@link CategoryDataset}.
 */
public class AreaChartDemo extends ApplicationFrame {

    /**
     * Creates a new demo application.
     *
     * @param title  the frame title.
     */
    public AreaChartDemo(final String title) {

        super(title);

        // create a dataset...
        final double[][] data = new double[][] {
            {1.0, 4.0, 3.0, 5.0, 5.0, 7.0, 7.0, 8.0},
            {5.0, 7.0, 6.0, 8.0, 4.0, 4.0, 2.0, 1.0}/*,
            {4.0, 3.0, 2.0, 3.0, 6.0, 3.0, 4.0, 3.0}*/
        };

        final CategoryDataset dataset = DatasetUtilities.createCategoryDataset(
                new String[]{"AeroHC","KernelAHC"}, new String[]{"50","100","150","200","250","300","350","400"}, data
        );

        // create the chart...
        final JFreeChart chart = createChart(dataset);
        final ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new Dimension(500, 270));
        chartPanel.setEnforceFileExtensions(false);

        setContentPane(chartPanel);

    }

    // ****************************************************************************
    // * JFREECHART DEVELOPER GUIDE                                               *
    // * The JFreeChart Developer Guide, written by David Gilbert, is available   *
    // * to purchase from Object Refinery Limited:                                *
    // *                                                                          *
    // * http://www.object-refinery.com/jfreechart/guide.html                     *
    // *                                                                          *
    // * Sales are used to provide funding for the JFreeChart project - please    * 
    // * support us so that we can continue developing free software.             *
    // ****************************************************************************

    /**
     * Creates a chart.
     * 
     * @param dataset  the dataset.
     * 
     * @return The chart.
     */
    private JFreeChart createChart(final CategoryDataset dataset) {

        final JFreeChart chart = ChartFactory.createAreaChart(
            "Area Chart",             // chart title
            "Category",               // domain axis label
            "Value",                  // range axis label
            dataset,                  // data
            PlotOrientation.VERTICAL, // orientation
            true,                     // include legend
            true,                     // tooltips
            false                     // urls
        );

        // NOW DO SOME OPTIONAL CUSTOMISATION OF THE CHART...

        // set the background color for the chart...
//        final StandardLegend legend = (StandardLegend) chart.getLegend();
  //      legend.setAnchor(StandardLegend.SOUTH);

        chart.setBackgroundPaint(Color.white);
        final TextTitle subtitle = new TextTitle("An area chart demonstration.  We use this "
            + "subtitle as an example of what happens when you get a really long title or "
            + "subtitle.");
        subtitle.setFont(new Font("SansSerif", Font.PLAIN, 12));
        subtitle.setPosition(RectangleEdge.TOP);
//        subtitle.setSpacer(new Spacer(Spacer.RELATIVE, 0.05, 0.05, 0.05, 0.05));
        subtitle.setVerticalAlignment(VerticalAlignment.BOTTOM);
        chart.addSubtitle(subtitle);

        final CategoryPlot plot = chart.getCategoryPlot();
        plot.setForegroundAlpha(0.5f);

  //      plot.setAxisOffset(new Spacer(Spacer.ABSOLUTE, 5.0, 5.0, 5.0, 5.0));
        plot.setBackgroundPaint(Color.lightGray);
        plot.setDomainGridlinesVisible(true);
        plot.setDomainGridlinePaint(Color.white);
        plot.setRangeGridlinesVisible(true);
        plot.setRangeGridlinePaint(Color.white);

        final CategoryAxis domainAxis = plot.getDomainAxis();
        domainAxis.setCategoryLabelPositions(CategoryLabelPositions.UP_45);        
        domainAxis.setLowerMargin(0.1);
        domainAxis.setUpperMargin(0.5);
        domainAxis.addCategoryLabelToolTip("Type 1", "The first type.");
        domainAxis.addCategoryLabelToolTip("Type 2", "The second type.");
        domainAxis.addCategoryLabelToolTip("Type 3", "The third type.");

        final NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
        rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
        rangeAxis.setLabelAngle(0 * Math.PI / 2.0);
        rangeAxis.setAutoRangeIncludesZero(false);
        // OPTIONAL CUSTOMISATION COMPLETED.

        return chart;

    }

    /**
     * Starting point for the demonstration application.
     *
     * @param args  ignored.
     */
    public static void main(final String[] args) {

        Log.getInstance().addTarget(new PrintStreamLogTarget());
        final AreaChartDemo demo = new AreaChartDemo("Area Chart Demo");
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);

    }

}

Answer 1

您可以在渲染器中配置：

    AreaRenderer renderer = (AreaRenderer) plot.getRenderer();
    renderer.setEndType(AreaRendererEndType.LEVEL);

Answer 2

为XYSeriesCollection使用dataset并切换为使用ChartFactory#createXYAreaChart。

您需要更改部分配置，因为您不会使用CategoryAxis

enter image description here

Answer 3

没有足够的代表评论大卫吉尔伯特的答案，所以我必须发表一个单独的答案。

在渲染器中配置truncate end类型时，我得到了所需的结果：

AreaRenderer renderer = (AreaRenderer) plot.getRenderer();
renderer.setEndType(AreaRendererEndType.TRUNCATE);

JFreeChart的面积图包括零

3 个答案: