I have a bunch of cross plots with two sets of data and have been looking for a matploltib way of highlighting their plotted regions with smoothed polygon outlines.
At the moment i just use Adobe Illustrator and amend saved plot, but this is not ideal. Example:
I'd be grateful for any pointers/links to examples.
Cheers
Here, you have an example. I was written the main ideas, but obviously, you could do it better.
A short explanations:
1) You need to compute the convex-hull (http://en.wikipedia.org/wiki/Convex_hull)
2) With the hull, you could scale it to keep all your data inside.
3) You must to interpolate the resulting curve.
The first part was done in http://wiki.scipy.org/Cookbook/Finding_Convex_Hull. The second one is trivial. The third one is very general, and you could perform any method, there are a lot of different ways to do the same. I took the @Jaime's approach (Smooth spline representation of an arbitrary contour, f(length) --> x,y), which I think it's a very good method.
I hope it help you...
There are some useful papers, eg.:
http://repositorium.sdum.uminho.pt/bitstream/1822/6429/1/ConcaveHull_ACM_MYS.pdf
Also, you could try with: http://resources.arcgis.com/en/help/main/10.1/index.html#//007000000013000000
I don't know nothing about arcgis, but it looks fine.