Create GitHub punch card like plots with JFreeChart

Question

I am looking for suggestions as how to create plots similar to GitHub punch cards with JFreeChart. E.g.

enter image description here

I guess it's some variant of a heat map, or two dimensional histogram.

0__ · Accepted Answer · 2013-10-14T10:56:06.733

Ok, so I found XYBubbleRenderer which looks like a good starting point.

create a MatrixSeries with rows = 7, columns = 24
fill in the frequencies accordingly. I found it useful to normalise the values first to 0...1, then take the square root (smaller values have a bit better visible circles), then multiply by 0.5 (otherwise the circles are too large)
create a MatrixSeriesCollection from that
use ChartFactory.createBubbleChart
the circle outline can only be removed via plot.getRenderer.setSeriesOutlinePaint(0, new Color(0, 0, 0, 0))
ensure integer tick units on both axis
x-axis range -0.5 to 23.5, y-axis range -0.5 to 6.5 (or 0.5 to 7.5 if you use Calendar.DAY_OF_WEEK)
custom NumberTickUnit for the y-axis to use day labels instead of numbers

The result:

enter image description here

And `yAxis.setInverted(true)` to have the week go from top to bottom — 0__, Oct 14 '13 at 16:26

trashgod · Answer 2 · 2018-03-14T07:54:50.023

2

In addition to XYBubbleRenderer, suggested here, also consider a suitable implementation of TableCellRenderer and Icon, illustrated here.

edited Mar 14 '18 at 07:54

answered Oct 14 '13 at 10:13

trashgod

1

Good point, thanks. I keep trying with JFreeChart, because I get good quality PDF, which is a bit more work with general Swing components and look-and-feel interaction. – 0__ Oct 14 '13 at 10:15

2 Answers2