> 
> Hello Grass users,
> 
> I have a raster data set registered to UTMs with 1 meter by 1 meter cells.  
> Values within the cells are either 0 or 1.  From this raster data set, I now
> want to create another raster data set over the same area but with 30 meter 
> 30 meter cells.  The value within each, new 30 meter cell will be the number 
> of 1 meter cells (for the same geographic space) which have a value of 1.
> Thus the range of POSSIBLE values within the new data set could range from 0
> (for zero 1 meter cells with a value 1) to 900 (where all 900 of the 1 meter
> cells had a value of 1).

I think r.mfilter could be the tool for you. Create a parallel filter
(30*30, or better 31*31 in order to have a center), set the divisor to 1,
after your result is calculated change the region to the 30m grid and
perform a r.mapcalc just with 'r.mapcalc a=b'. Hope this works.

Stefan Jaeger				currently at
Dept. of Geography			USGS	
University of Heidelberg		National Center
INF 348					Reston, VA 22092
69120 Heidelberg			USA
Germany
stefan@geo0.geog.uni-heidelberg.de	sjaeger@resdgs2.er.usgs.gov

*********  sorry, no fancy name tag  *********

> 
> I have several data sets to convert, with the 30 meter data sets containing
> 500 rows by 500 columns.
> 
> Any help or ideas would be greatly appreciated.
> 
> Thanks,
> 
> Mark Gregory                    mg@soil.agr.okstate.edu
> Oklahoma State University       (405) 744-6417
> Stillwater,OK  74078            (405) 744-5269 (fax)
> 


