Change the starting value of value axis in Bar chart with Jfreechart

Question

I have the following values to be shown in a BAR chart in my Java web application. 9.46373791E8 9.45942547E8 9.45559945E8 9.45187023E8 9.44856693E8 9.44417826E8 9.44007878E8

As u can see the values are really close and have minor differences. When i generate a bar chart using Jfreechart, all the bars appear almost the same height and there is no way of telling the difference visually. So i want to change the (0,0) to (0,9)so that x axis is at number 9 on y axis. I still want to show the real values that the bars represent somewhere on top of the bar.

please suggest ideas. i tried the below but it didnt work

    Double d=(double) 9;
ValueAxis rangeAxis = plot.getRangeAxis();
rangeAxis.setLowerMargin(d);

Edit: This is my original program for your reference

JFreeChart chart =
            ChartFactory.createBarChart(
                    title,
            "File Date",
            "File Size",
            dataset,
            PlotOrientation.VERTICAL,
            true,
            true,
            false);
         chart.setBackgroundPaint(Color.white);



      // Set the background color of the chart
        chart.getTitle().setPaint(Color.DARK_GRAY);
        chart.setBorderVisible(true);
        // Adjust the color of the title
        CategoryPlot plot = chart.getCategoryPlot();
        plot.getRangeAxis().setLowerBound(d);
        // Get the Plot object for a bar graph

        plot.setBackgroundPaint(Color.white);     
        plot.setRangeGridlinePaint(Color.blue);
        CategoryItemRenderer renderer = plot.getRenderer();
        renderer.setSeriesPaint(0, Color.decode("#00008B"));

Answer 1

Since the y-axis in your example is an instance of NumberAxis you can call the method setAutoRangeIncludesZero() on the axis (passing false for the new value of the flag).
Then, even if you add new data to the dataset, the axis range will be updated correctly (whereas calling setLowerBound() will fix the axis range with the lower bound you specify, and disable the auto-range feature).

Answer 2

I guess you want to do the following:

barChart.getCategoryPlot().getRangeAxis().setLowerBound(9.0);

where barChart is you JFreeChart Object.

But since yours values are above 9.0E8 ( IT'S OVER 9000), shouldn't you put the lower bound at 9.0E8 instead of 9.0 since at there is not so much difference between 0 and 9 when you are at 9.0E8 and beyond.

EDIT: I've tested your code and it's working on my computer under Windows Vista...

My full code is here:

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

import javax.swing.JFrame;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.CategoryItemRenderer;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;

public class ChartTester extends JFrame {

    private static final long serialVersionUID = 1L;

    public ChartTester(final String title) {
        super(title);
        this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        final CategoryDataset dataset = createDataset();
        final JFreeChart chart = createChart(dataset);
        final ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new Dimension(500, 270));
        setContentPane(chartPanel);

    }

    /**
     * Returns a sample dataset.
     * @return The dataset.
     */
    private CategoryDataset createDataset() {
        final String rowName = "Row";
        final String[] columnName = { "Column1","Column2","Column3","Column4","Column5"};
        final DefaultCategoryDataset dataset = new DefaultCategoryDataset();

        dataset.addValue(9.2, rowName, columnName[0]);
        dataset.addValue(9.3, rowName, columnName[1]);
        dataset.addValue(9.4, rowName, columnName[2]);
        dataset.addValue(9.5, rowName, columnName[3]);
        dataset.addValue(10.0, rowName, columnName[4]);

        return dataset;
    }

    /**
     * Creates a sample chart.
     * @param dataset  the dataset.
     * @return The chart.
     */
    private JFreeChart createChart(final CategoryDataset dataset) {
        double d =9.0;
        final JFreeChart chart =
            ChartFactory.createBarChart(
                    "Chart Title",
                    "X Axis",
                    "Y Axis",
                    dataset,
                    PlotOrientation.VERTICAL,
                    true,
                    true,
                    false);
        chart.setBackgroundPaint(Color.white);  
        // Set the background color of the chart
        chart.getTitle().setPaint(Color.DARK_GRAY);
        chart.setBorderVisible(true);
        // Adjust the color of the title
        CategoryPlot plot = chart.getCategoryPlot();
        plot.getRangeAxis().setLowerBound(d);
        // Get the Plot object for a bar graph
        plot.setBackgroundPaint(Color.white);     
        plot.setRangeGridlinePaint(Color.blue);
        CategoryItemRenderer renderer = plot.getRenderer();
        renderer.setSeriesPaint(0, Color.decode("#00008B"));
        return chart;
    }

    public static void main(final String[] args) {
        final ChartTester test = new ChartTester("Test");
        test.pack();
        test.setVisible(true);
    }
}