[R-sig-Geo] random samples of a grid

[Jeffrey Stratford]

Hi,  is there a way to sample an ESRI grid using random sample points? 
In the past I used ESRI's spatial analyst but I would like to switch all
my analyses to R if possible.  The grid is from the National Land Cover
Dataset  (30m res, 7 landcover classes).  I had roadside points from
which I extracted data such as % grassland, % pine, etc in buffers of
90, 210, and 990 m radii.  I would like to generate 200 random samples
from the same map to compare the roadside points to random samples (and,
hopefully, there are no differences).   Make sense?  Hope so. 

Thanks,

Jeff

****************************************
Jeffrey A. Stratford, Ph.D.
Postdoctoral Associate
331 Funchess Hall
Department of Biological Sciences
Auburn University
Auburn, AL 36849
334-329-9198
FAX 334-844-9234
http://www.auburn.edu/~stratja