This is a long-standing known issue with the contour code. The contouring library we are using (in cntr.c) was written for a graphics library that did not support compound paths, so to draw a donut-shaped objects it creates "cut paths" from the inner to outer edge. A number of the matplotlib developers have taken stabs at changing this behavior over the years, but it is a very opaque chunk of code, and none of us have managed it without introducing new more serious errors. A fresh set of eyes may be able to sort it out, and we do have compound path support in all backends (save the mostly obsolete Gdk) now. Replacing the contouring code with something else that is license-compatible is also an option, but I wasn't able to find anything suitable last time I looked (which was a long time ago now).
Cheers, Mike Joseph Smidt wrote: > I am making contourf plots with some transparency as I want to > eventually overlay such plots. When I plot such plots I see artifacts > or lines that shouldn't be there as seen here: > http://josephsmidt.googlepages.com/ex.png > > Is this a bug or am I plotting incorrectly? My script is here: > http://josephsmidt.googlepages.com/plotex.py and the data needed for > the plot is here: http://josephsmidt.googlepages.com/exCHI.txt > > However, the relevant part of the code for plotting I'll just cut and > paste here: > > levels = [x0, x1, x2, x3] > contourf(Y,X,transpose(CHI),levels,alpha=0.7) > show() > > Thanks. > > Joseph Smidt > > > -- Michael Droettboom Science Software Branch Operations and Engineering Division Space Telescope Science Institute Operated by AURA for NASA ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
