Tuesday, March 06, 2007

Charts with JFreeChart 1

JFreeChart is a free Java chart library that can be used to display charts from Java applications. It features:
  • A wide range of chart types
  • support for many output types, including Swing components, image files (including PNG and JPEG), and vector graphics file formats (including PDF, EPS and SVG);
  • It is distributed under the terms of the LGPL, which permits use in proprietary applications.
In this post, I will describe how to use JFreeChart to display a comparative barchart, with data that contains multiple series which have to be grouped (G1, G2) per date. This effectively gives three levels of information (series, group and date). In order to display this data in a chart, we can use a StackedBarChart from JFreeChart. Please note that this is a result of my playing around with JFreeChart, and is not from the official documentation, which means that some of my assumptions may not be accurate. Follow these steps to run the example
  1. Download JFreeChart from here.
  2. Create the DataSet: The StakedBarChart takes a CategoryDataset as input. The following piece of code shows how to add data to the CategoryDataset.
      DefaultCategoryDataset dataSet = new DefaultCategoryDataset();

    dataSet.addValue(100, "Series1 G1", "Jan 04");
    dataSet.addValue(150, "Series1 G2", "Jan 04");
    It is important to note that the order in which you add data to the Dataset, as this would affect how you assign colors to the different series.
  3. Create the renderer and assign series colors:
      GroupedStackedBarRenderer renderer = new GroupedStackedBarRenderer();
    renderer.setItemMargin(0.01);
    renderer.setDrawBarOutline(false);

    renderer.setSeriesPaint(0, Color.blue);
    renderer.setSeriesPaint(1, Color.blue);
    The order of the series in the Dataset, will dictate series number when assigning colors. You will see this in the full code shown below.
  4. Map series to groups: This is done using the KeyToGroupMap.
      KeyToGroupMap keytogroupmap = new KeyToGroupMap("G1");
    keytogroupmap.mapKeyToGroup("Series1 G1", "G1");
    keytogroupmap.mapKeyToGroup("Series2 G1", "G1");
  5. Create the Legend: Since I wanted to give same color to a given series in different groups, I had to add a legend collection that maps colors to the series
     private static LegendItemCollection createLegendItems() {
    LegendItemCollection legenditemcollection = new LegendItemCollection();
    LegendItem legenditem = new LegendItem("Series1", "-", null, null, Plot.DEFAULT_LEGEND_ITEM_BOX, Color.blue);
    LegendItem legenditem1 = new LegendItem("Series2", "-", null, null, Plot.DEFAULT_LEGEND_ITEM_BOX, Color.cyan);
    LegendItem legenditem2 = new LegendItem("Series3", "-", null, null, Plot.DEFAULT_LEGEND_ITEM_BOX, Color.green);
    LegendItem legenditem3 = new LegendItem("Series4", "-", null, null, Plot.DEFAULT_LEGEND_ITEM_BOX, Color.yellow);
    legenditemcollection.add(legenditem);
    legenditemcollection.add(legenditem1);
    legenditemcollection.add(legenditem2);
    legenditemcollection.add(legenditem3);
    return legenditemcollection;
    }
  6. The code
    package chart;

    import java.awt.Color;

    import org.jfree.chart.ChartFactory;
    import org.jfree.chart.ChartFrame;
    import org.jfree.chart.JFreeChart;
    import org.jfree.chart.LegendItem;
    import org.jfree.chart.LegendItemCollection;
    import org.jfree.chart.axis.SubCategoryAxis;
    import org.jfree.chart.plot.CategoryPlot;
    import org.jfree.chart.plot.Plot;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.chart.renderer.category.GroupedStackedBarRenderer;
    import org.jfree.data.KeyToGroupMap;
    import org.jfree.data.category.CategoryDataset;
    import org.jfree.data.category.DefaultCategoryDataset;

    public class StackedBarChartTest {

    private static CategoryDataset getData() {
    DefaultCategoryDataset dataSet = new DefaultCategoryDataset();

    dataSet.addValue(100, "Series1 G1", "Jan 04");
    dataSet.addValue(150, "Series1 G2", "Jan 04");

    dataSet.addValue(60, "Series2 G1", "Feb 04");
    dataSet.addValue(90, "Series2 G2", "Feb 04");

    dataSet.addValue(70, "Series3 G2", "Feb 04");
    dataSet.addValue(99, "Series3 G1", "Feb 04");

    dataSet.addValue(100, "Series4 G1", "Feb 04");
    dataSet.addValue(80, "Series4 G2", "Feb 04");

    dataSet.addValue(20, "Series1 G1", "Feb 04");
    dataSet.addValue(50, "Series1 G2", "Feb 04");

    dataSet.addValue(10, "Series2 G1", "Jan 04");
    dataSet.addValue(40, "Series2 G2", "Jan 04");

    dataSet.addValue(10, "Series3 G2", "Jan 04");
    dataSet.addValue(50, "Series3 G1", "Jan 04");

    dataSet.addValue(10, "Series4 G1", "Jan 04");
    dataSet.addValue(60, "Series4 G2", "Jan 04");

    // dataSet.addValue(100, "Series1 G1", "Jan 04");
    // dataSet.addValue(20, "Series1 G1", "Feb 04");
    // dataSet.addValue(10, "Series2 G1", "Jan 04");
    // dataSet.addValue(60, "Series2 G1", "Feb 04");
    // dataSet.addValue(99, "Series3 G1", "Feb 04");
    // dataSet.addValue(50, "Series3 G1", "Jan 04");
    // dataSet.addValue(100, "Series4 G1", "Feb 04");
    // dataSet.addValue(10, "Series4 G1", "Jan 04");
    //
    //
    // dataSet.addValue(150, "Series1 G2", "Jan 04");
    // dataSet.addValue(50, "Series1 G2", "Feb 04");
    // dataSet.addValue(40, "Series2 G2", "Jan 04");
    // dataSet.addValue(90, "Series2 G2", "Feb 04");
    // dataSet.addValue(10, "Series3 G2", "Jan 04");
    // dataSet.addValue(70, "Series3 G2", "Feb 04");
    // dataSet.addValue(60, "Series4 G2", "Jan 04");
    // dataSet.addValue(80, "Series4 G2", "Feb 04");

    return dataSet;
    }

    private static JFreeChart createChart(CategoryDataset categorydataset) {
    JFreeChart jfreechart = ChartFactory.createStackedBarChart("Sample", null, "value", categorydataset, PlotOrientation.VERTICAL, true, true, false);
    GroupedStackedBarRenderer renderer = new GroupedStackedBarRenderer();
    renderer.setItemMargin(0.01);
    renderer.setDrawBarOutline(false);

    renderer.setSeriesPaint(0, Color.blue);
    renderer.setSeriesPaint(1, Color.blue);

    renderer.setSeriesPaint(2, Color.cyan);
    renderer.setSeriesPaint(3, Color.cyan);

    renderer.setSeriesPaint(4, Color.green);
    renderer.setSeriesPaint(5, Color.green);

    renderer.setSeriesPaint(6, Color.yellow);
    renderer.setSeriesPaint(7, Color.yellow);

    // renderer.setSeriesPaint(0, Color.blue);
    // renderer.setSeriesPaint(4, Color.blue);
    //
    // renderer.setSeriesPaint(1, Color.cyan);
    // renderer.setSeriesPaint(5, Color.cyan);
    //
    // renderer.setSeriesPaint(2, Color.green);
    // renderer.setSeriesPaint(6, Color.green);
    //
    // renderer.setSeriesPaint(3, Color.yellow);
    // renderer.setSeriesPaint(7, Color.yellow);

    KeyToGroupMap keytogroupmap = new KeyToGroupMap("G1");
    keytogroupmap.mapKeyToGroup("Series1 G1", "G1");
    keytogroupmap.mapKeyToGroup("Series2 G1", "G1");
    keytogroupmap.mapKeyToGroup("Series3 G1", "G1");
    keytogroupmap.mapKeyToGroup("Series4 G1", "G1");

    keytogroupmap.mapKeyToGroup("Series1 G2", "G2");
    keytogroupmap.mapKeyToGroup("Series2 G2", "G2");
    keytogroupmap.mapKeyToGroup("Series3 G2", "G2");
    keytogroupmap.mapKeyToGroup("Series4 G2", "G2");

    renderer.setSeriesToGroupMap(keytogroupmap);
    SubCategoryAxis subcategoryaxis = new SubCategoryAxis("Series/Month");
    subcategoryaxis.setCategoryMargin(0.03);
    subcategoryaxis.addSubCategory("G1");
    subcategoryaxis.addSubCategory("G2");

    CategoryPlot categoryplot = (CategoryPlot) jfreechart.getPlot();
    categoryplot.setDomainAxis(subcategoryaxis);
    categoryplot.setRenderer(renderer);
    categoryplot.setFixedLegendItems(createLegendItems());

    return jfreechart;
    }

    private static LegendItemCollection createLegendItems() {
    LegendItemCollection legenditemcollection = new LegendItemCollection();
    LegendItem legenditem = new LegendItem("Series1", "-", null, null, Plot.DEFAULT_LEGEND_ITEM_BOX, Color.blue);
    LegendItem legenditem1 = new LegendItem("Series2", "-", null, null, Plot.DEFAULT_LEGEND_ITEM_BOX, Color.cyan);
    LegendItem legenditem2 = new LegendItem("Series3", "-", null, null, Plot.DEFAULT_LEGEND_ITEM_BOX, Color.green);
    LegendItem legenditem3 = new LegendItem("Series4", "-", null, null, Plot.DEFAULT_LEGEND_ITEM_BOX, Color.yellow);
    legenditemcollection.add(legenditem);
    legenditemcollection.add(legenditem1);
    legenditemcollection.add(legenditem2);
    legenditemcollection.add(legenditem3);
    return legenditemcollection;
    }

    public static void main(String args[]) {

    StackedBarChartTest demo = new StackedBarChartTest();

    ChartFrame frame = new ChartFrame("First", demo.createChart(demo.getData()));
    frame.pack();
    frame.setVisible(true);
    }
    }
    Note:
    • The SubCategoryAxis is used to assign labels to Category Axis' subcategories (i.e. groups).
    • The ChartFrame is used to display the results. The results could also be written to an output stream using the ChartUtilities.writeChartAsJPEG or ChartUtilities.writeChartAsPNG methods.
    • The commented lines show how the series color is affected by the order in which the data is entered into the Dataset.

17 comments:

  1. Hi.. Abhi...

    Can u help me regarding the way of running the Jfreechart code??? It will be very much helpful for me if u can help me out.. I am stuck with it for many days.. My email id is : abh.kol@gmail.com. . .

    With regards,
    Abhisek

    ReplyDelete
  2. hi Abhi

    i am a new user of JFreechart and i wud like to create an Image Map for the Horizontal Stacked Bar chart.
    i did that too. but mapping was a problem. how to set the tooltip, etc...

    ReplyDelete
  3. bablu

    hi abhi
    can u tell me how to create the
    legends in square/circle shape in pie
    and bar charts. Its very urgent.
    Bye

    ReplyDelete
  4. I want my bar to be clickable like each different bar can point to some different url. Would you plz tell me how to do that?Any help/hint or resource reference from you would be appreciated.
    Thanks,
    Suvoraj

    ReplyDelete
  5. hi Abhi
    Can you please send me the jar that have org.jfree.chart.renderer.category

    Thanks
    With Regards
    Pankaj Bansal
    pankaj.bansal@sdgc.com

    ReplyDelete
  6. hi abhi ,

    i am not able to run the javachart it is giving me the error package org.jfree.util does not exit.

    ReplyDelete
  7. Hi.. Abhi...

    Can u help me regarding the way of running the Jfreechart code??? It will be very much helpful for me if u can help me out.. I am stuck with it for many days.. My email id is ravi.k.choudhari@gmail.com

    thnks.

    ReplyDelete
  8. Hi Abhi

    It would be of great help if you could pls tell me how to assign the series color based on some field value which is being queried from database. I am using JasperReports for the same.

    ReplyDelete
  9. Hi Abhi,

    Is there a way to change the orientation of the SubCategroyAxis, for rg: In your case change the orientation of G1 , G2 label by 90 degrees.

    Regards
    Naveen

    ReplyDelete
  10. Hi Abhi....

    I need some hlep regarding charts, please help me i need financial charts like line charts,candlestick charts and like that

    With Regards,
    Dhanavardhan

    ReplyDelete
  11. Hi Abhi,

    i'm working on bar chart using JFREEChart.
    i'm able to get dynamic data but i'm unable to run on browser if i'm runing on browser its giving default image.Help me out
    my mail id is rajnesh.thakore@gmail.com

    ReplyDelete
  12. Hi Abhi
    i am a new user of JFreechart and i wud like to create a pie chart in IBM WebSphere Studio Application Developer 5.1.1
    Any help/hint or resource reference from you would be appreciated.
    Thanks,
    Anamika

    ReplyDelete
  13. HI Abhi...
    I have an urgent requirement to plott bar chart graphs.
    I'm new to plotting graphs can u please explain me how to plott graphs using java...

    thanks inadvance..

    ReplyDelete
  14. Hi Abhi,
    Which version of JFreeChart do you have? I have v1.0.5 and your code does not work on it.

    ReplyDelete
  15. hi abhi

    how did u create a categories archive in ur blog at the left side, i want to do the same for my blog but don't know how to do this.

    thanks

    ReplyDelete
  16. Hi Abhi,
    Thank you so much for the Legend items code.It has helped me a lot and saved a lot of my API research time. I need one more help, can you tell me how can i put a image title to a bar chart instead of default text title.

    Thank you sooo much,
    Prashant

    ReplyDelete
  17. The explanation is correct but the code is not working,in Jfree Chart
    There are some limitations with respect to the item labels in the current release of JFreeChart:
    • some renderers do not support item labels;
    • axis ranges are not automatically adjusted to take into account the item labels—some labels may disappear off the chart if sufficient margins are not set (use the setUpperMargin() and/or setLowerMargin() methods in the relevant axis to adjust this).

    ReplyDelete