[R] Returning contour co-ordinates

[John Field]

Dear R-helpers,

I'd like to be able to post-process contours coming from contour().   Does 
anyone have a version of contour() (or something similar) which will return 
the contour coordinates?

In searching the archives I've come across a message in Nov 01 which had 
this on a wish-list, but I can find no later reference.

With thanks,
John Field
Adelaide, South Australia