Re: [Matplotlib-users] Artefacts in contour plot?

[Dominique O. <Dom...@po...>]

(Sorry, sending this again to correct a typo -- i inverted small and 
large below)

I have made several experiments; I have installed the latest matplotlib
(with the 'contour' update) in both Win XP and SuSE Linux Pro 9.1. I
made sure to uninstall everything pertaining to matplotlib before
installing the latest version. In Windows, I use the pre-built
distribution, and in Linux I compile it myself. The situation is this:

- In Linux, some zigzagging lines appear when there are few points to
interpolate. Eg, if i generate my grid from
	x = y = arange( -1, 1, delta ),
zigzags would appear for LARGE values of delta (eg, delta = 0.2; ie too 
few values of x and/or y). However, it seems that those zigzags are a 
normal consequence of a large value of delta. For SMALLER deltas, the 
contours are beautiful.

- In XP, the same as above happens. But I see additional lines that
don't seem to represent anything meaningful. I made sure I was
performing a clean install. Are there updates to other packages I should
consider? Pygtk? This happened with both the TkAgg and GTKAgg backends.
Perhaps I should try compiling matplotlib myself?

If anyone is able to reproduce the problem, then it might indeed be a
problem. If not, perhaps something is funny with my box.

Thanks,
Dominique