Thousands, millions, billions, & gazillions?

[DavidThi808]

Hi;

Is there a way to tell an axis to divide all numbers by 1,000; 1,000,000; and 1,000,000,000 so if all my values are 1,000 - 29,000 the axis is 1 - 29?

thanks - dave

ps - what order of magnitude is a gazillion?

[jwenting]

there's no such number as a "gazillion". It's just a figure of speech, rather like "1, 2, many" and indicates any number large enough to be incomprehensible.

[RichardWest]

ps - what order of magnitude is a gazillion?

There isn't. Gazillion is yet-another-made-up number. See this Wikipedia entry for some interesting history and examples.

[DavidThi808]

ps - what order of magnitude is a gazillion?

Sorry, I guess I should have put a after the ps - that part was a joke.

Seriously - can the axis be set to divide all values for thou/mil/bil?

[RichardWest]

Sorry, I guess I should have put a after the ps - that part was a joke.

I knew it was a joke. It just sparked my curiousity as to the origin of fictious numbers. That is why I supplied the link.

Seriously - can the axis be set to divide all values for thou/mil/bil?

Now that I have thought about this, I believe the easiest way to do this would be to keep the data intact and change the tick labels. You want to keep the data as 1,500,000 instead of 1.5 (for instance) in case you wish to use the data in another location. You can change the tick labels in several ways: create a custom TickUnitSource, override the axis' refreshTicks(), or create a NumberFormat that divides the source by the desired order of magnitude.

[DavidThi808]

I overrode NumberFormat and it works great - piece of cake.

thanks - dave

[david.gilbert]

I overrode NumberFormat and it works great - piece of cake.

That's the approach I would have suggested if I'd got to this thread sooner. I'm interested in adding a few more number formatting options to JFreeChart, so if your code is fit for general purpose use and you feel like contributing it, let me know.

[DavidThi808]

Here you go - it is a large and very complex class:

Code: Select all

public class DivNumberFormat extends DecimalFormat {

	private int magnitude;

	public DivNumberFormat(int magnitude) {
		this.magnitude = magnitude;
	}

	public StringBuffer format(double number, StringBuffer result, FieldPosition fieldPosition) {
		return super.format(number / magnitude, result, fieldPosition);
	}

	public StringBuffer format(long number, StringBuffer result, FieldPosition fieldPosition) {
		return super.format(number / magnitude, result, fieldPosition);
	}
}

[RichardWest]

Now, if only we had a means to link the magnitude into the label of the axis using this formatter. For example, have the axis label be "counts (in thousands)" or "counts (in 1000s)" when the magnitude is 1000. Now that would be rather nifty. I think extending the NumberAxis class, automatically assigning a DivNumberFormat object, and providing a getter that returns the magnitude should do the trick. This would also allow you to change the scaling on the fly. As long as an AxisChangeEvent is fired, the chart will redraw with the updates.

[DavidThi808]

Hi;

You guys know much better than me what is needed as you read this daily. But the 2 main things I think you need for the number is a multiplier (which normally would be values like 0.001, 0.000001, ...) and a pattern for the formatter.

thanks - dave

[RichardWest]

I'm interested in adding a few more number formatting options to JFreeChart, so if your code is fit for general purpose use and you feel like contributing it, let me know.

My only suggestion before adding it would be to change the name to ScaledDecimalFormat or ScaledNumberFormat. IMHO, this seems like a slightly more descriptive name. I will also start work on the axis as well.