Local maxima/minima

Hi all,

I'm currently plotting 2 dimensional data sets using contourf and pcolor.
I'd like to add on to these plots markers at the local maxima and minima.
I can do this using scatter but the problem is finding the max/min in the
first place.

I'm currently using a brute force nested for loop which compares the value
at each point with a square slice around it, but this is painfully slow (5
or 6 seconds for a 75x75 maxtrix). I was wondering if this is already
implemented somewhere in matplotlib (or anywhere else for that matter) or
if someone has come up against this problem before.


Tim Leslie

PS. John, have you considered starting a #matplotlib channel on IRC at