New subject: Matrix sunburst: increasing the separation between arcs

27 Nov 2015

Hi,

Pair programming with Milton at Smalltalks 2015, we (well mostly he) 
came with what I call a "matrix sunburst" that shows a sunburst diagram 
using a matrix instead of a tree as data source (the clever hack of 
Milton was to convert the data in the matrix to a tree with only one 
child on any branch after the first one!). The inspiration was taken 
from [1] and the idea was from a friend who want to use this kind of 
matrix alike sunburst to compare public medicine information.

[1] 
http://www.theguardian.com/world/interactive/2012/may/08/gay-rights-united-…

With this I can create thinks like this:

But to get a more readable visualization, I would like to make two things:

a. Increase the empty space between arcs, not like the current radial 
strategy, but more like the graphic at [1]. For this we thought in 
adding a RTEdge with the same color as the background. How can I 
calculate the position of every RTEdge at the final of each arch in the 
sunburst?

b. I would like to keep each ring of the same size instead of making 
them narrower as the become more away of the center. It this possible?

c. Finally I have created RTSunburstBuilder>>exploreMatrix: aMatrix 
coloredWith: aColorPalette in my own image, because I think that is the 
best place it can be to be reused in my own visualizations. Is this a 
good practice? Can I share this code back with the Roassal project? How? 
(hopefully I will not need to learn git and its gratituous complexity).

Cheers,

Offray