Setting the lower limit of a LogAxis to zero creates a blank chart

[JP95Git]

Hi,

I use JFreeChart 1.5.2 to display various things. One of my testers discovered that if he sets the lower limit (setLowerBound) of the LogAxis to zero, a blank chart is shown. It happens in all charts, which uses a LogAxis. If I replace LogAxis with NumberAxis, everything works without a problem.

Here is some example code, which runs as a Tomcat webapp:

try (OutputStream out = response.getOutputStream();) {
	String axisName = "Pressure";
	JFreeChart chart = ChartFactory.createTimeSeriesChart("", "Date", axisName, seriesCollection, true, false, false);
	XYPlot plot = (XYPlot) chart.getPlot();

	LogAxis rangeLogAxis = new LogAxis(axisName);
	// Customize the axis..., but this does not affect the bug.
	plot.setRangeAxis(rangeLogAxis);
	if (minY != null) {
		rangeLogAxis.setLowerBound(minY.doubleValue());
	}
	if (maxY != null) {
		rangeLogAxis.setUpperBound(maxY.doubleValue());
	}
	ChartUtils.writeChartAsPNG(out, chart, 800, 600);
}

minY and maxY are the lower and upper limit of the axis, which can be changed by the user.

Setting a very small value like 0.1 instead of zero creates my chart again and is a nice workaround, but zero should work too.

[trashgod]

As the logarithm approaches negative infinity for arguments approaching zero, why not use the initial minimum range value, 0.01, or getSmallestValue()?