CODEWITHSUNDEEP
javajfreechart
Evan
Evan

Reputation: 191

JFreeChart set labels for error

I'm using JFreeChart to graph some data, and I've set it up so that the graph shows my standard error for each point as such: Graph

The label shows the Y value for each point, but I'd like to be able to show the Y value for the standard errors as well. Furthermore, is there a way to make it so this data only shows up if hovered over with the mouse?

This is the code I use to add both the error and the labels:

XYErrorRenderer renderer = new XYErrorRenderer();
renderer.setBaseLinesVisible(true);
renderer.setBaseShapesVisible(true);
renderer.setBaseItemLabelGenerator(new StandardXYItemLabelGenerator("{2}",
    NumberFormat.getNumberInstance(),NumberFormat.getNumberInstance()));
renderer.setBaseItemLabelsVisible(true);
chart.getXYPlot().setRenderer(renderer);

Thanks in advance.

Upvotes: 2

Views: 387

Answers (1)

trashgod
trashgod

Reputation: 205875

XYErrorRenderer inherits its implementation of drawItemLabel() from the abstract parent, which knows nothing about the error bars. You'll need to override drawItem() in a custom renderer subclass to draw the extra labels. The source for drawItemLabel() may serve as a guide.

Addendum: A less ambitious alternative would be to display the error range in a tooltip. The custom StandardXYToolTipGenerator below specifies a custom format string and overrides createItemArray() to supply the relevant y values from the dataset. As your XYDataset is a YIntervalSeriesCollection, you can cast it as shown below.

image

renderer.setBaseToolTipGenerator(new StandardXYToolTipGenerator(
        "{0}: {1}…{2}", NumberFormat.getInstance(), NumberFormat.getInstance()) {
    @Override
    protected Object[] createItemArray(XYDataset data, int series, int item) {
        YIntervalSeriesCollection d = (YIntervalSeriesCollection) data;
        Object[] result = new Object[3];
        double y = d.getYValue(series, item);
        result[0] = getYFormat().format(y);
        double min = d.getStartYValue(series, item);
        result[1] = getYFormat().format(min);
        double max = d.getEndYValue(series, item);
        result[2] = getYFormat().format(max);
        return result;
    }
});

Upvotes: 2

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