Area chart in JFreeChart includes zero - jfreechart

Question

Here is how my area chart in JFreeChart looks like. The area chart starts from 0 and rises up to the first value 5 or 1. Also after 400 on the y axis it falls down back to zero. I want it to start from 5 or 1 and not fall back to 0 after 400.
Area Chart http://imageshack.com/a/img837/6572/2ab0.jpg
Given below is the code. How do I fix it to avoid the zero?
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

You can configure this in the renderer:
AreaRenderer renderer = (AreaRenderer) plot.getRenderer();
renderer.setEndType(AreaRendererEndType.LEVEL);

Answer 2

Use an XYSeriesCollection for your dataset and switch to using ChartFactory#createXYAreaChart.
You will need to change some of the configuration as you will not be using a CategoryAxis

Answer 3

Not enough rep to comment on David Gilbert's answer, so I have to post a separate answer.
I had the desired results when configuring the truncate end type in the renderer:
AreaRenderer renderer = (AreaRenderer) plot.getRenderer();
renderer.setEndType(AreaRendererEndType.TRUNCATE);