Plot a Line Chart using jFreechart

Plot a Line Chart using jFreechart

This tutorial is aimed at describing to you how to plot a line chart using jFreechart. jFreechart is an external Java API used for plotting different types of charts including Bar Chart, Time Series etc.

Here we will show you a demo stating the steps to Plot a Line Chart using jFreechart (in codes), this codes were Provided by Object Refinery Limited and Contributors, who are a leading Programming firm that designed the jFreechart API (http://www.object-refinery.com/)

Line Chart

Fig 1: Showing three different kind of Plots on a sample JFreechart plot


/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.] *
* ——————-
* LineChartDemo6.java
* ——————-
* (C) Copyright 2004, by Object Refinery Limited and Contributors.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* $Id: LineChartDemo6.java,v 1.5 2004/04/26 19:11:55 taqua Exp $
*
* Changes
* ——-
* 27-Jan-2004 : Version 1 (DG);
*
*/
package org.jfree.chart.demo;

import java.awt.Color;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;
import org.jfree.ui.Spacer;

/**
* A simple demonstration application showing how to create a line chart using data from an
* {@link XYDataset}.
*
*/
public class LineChartDemo6 extends ApplicationFrame {

/**
* Creates a new demo.
*
* @param title the frame title.
*/
public LineChartDemo6(final String title) {

super(title);

final XYDataset dataset = createDataset();
final JFreeChart chart = createChart(dataset);
final ChartPanel chartPanel = new ChartPanel(chart);
chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));
setContentPane(chartPanel);

}

/**
* Creates a sample dataset.
*
* @return a sample dataset.
*/
private XYDataset createDataset() {

final XYSeries series1 = new XYSeries(“First”);
series1.add(1.0, 1.0);
series1.add(2.0, 4.0);
series1.add(3.0, 3.0);
series1.add(4.0, 5.0);
series1.add(5.0, 5.0);
series1.add(6.0, 7.0);
series1.add(7.0, 7.0);
series1.add(8.0, 8.0);

final XYSeries series2 = new XYSeries(“Second”);
series2.add(1.0, 5.0);
series2.add(2.0, 7.0);
series2.add(3.0, 6.0);
series2.add(4.0, 8.0);
series2.add(5.0, 4.0);
series2.add(6.0, 4.0);
series2.add(7.0, 2.0);
series2.add(8.0, 1.0);

final XYSeries series3 = new XYSeries(“Third”);
series3.add(3.0, 4.0);
series3.add(4.0, 3.0);
series3.add(5.0, 2.0);
series3.add(6.0, 3.0);
series3.add(7.0, 6.0);
series3.add(8.0, 3.0);
series3.add(9.0, 4.0);
series3.add(10.0, 3.0);

final XYSeriesCollection dataset = new XYSeriesCollection();
dataset.addSeries(series1);
dataset.addSeries(series2);
dataset.addSeries(series3);

return dataset;

}

/**
* Creates a chart.
*
* @param dataset the data for the chart.
*
* @return a chart.
*/
private JFreeChart createChart(final XYDataset dataset) {

// create the chart…
final JFreeChart chart = ChartFactory.createXYLineChart(
“Line Chart Demo 6”, // chart title
“X”, // x axis label
“Y”, // y axis label
dataset, // data
PlotOrientation.VERTICAL,
true, // include legend
true, // tooltips
false // urls
);

// NOW DO SOME OPTIONAL CUSTOMISATION OF THE CHART…
chart.setBackgroundPaint(Color.white);

// final StandardLegend legend = (StandardLegend) chart.getLegend();
// legend.setDisplaySeriesShapes(true);

// get a reference to the plot for further customisation…
final XYPlot plot = chart.getXYPlot();
plot.setBackgroundPaint(Color.lightGray);
// plot.setAxisOffset(new Spacer(Spacer.ABSOLUTE, 5.0, 5.0, 5.0, 5.0));
plot.setDomainGridlinePaint(Color.white);
plot.setRangeGridlinePaint(Color.white);

final XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer();
renderer.setSeriesLinesVisible(0, false);
renderer.setSeriesShapesVisible(1, false);
plot.setRenderer(renderer);

// change the auto tick unit selection to integer units only…
final NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
// OPTIONAL CUSTOMISATION COMPLETED.

return chart;

}

// ****************************************************************************
// * 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. *
// ****************************************************************************

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

final LineChartDemo6 demo = new LineChartDemo6(“Line Chart Demo 6”);
demo.pack();
RefineryUtilities.centerFrameOnScreen(demo);
demo.setVisible(true);

}

}

There are two important method in this implementation, the method createDataset() and method createChart(). The createDataset() method creates the dataset that will be embedded on the chart, while the createChart() creates the Chart to hold and display the Dataset