[GRASSLIST:34] r.mapcalc evaluation order

[Jan Hartmann]

Hi,

I am running r.mapcalc on the LandScan world population database 
(www.ornl.gov/gist/projects/LandScan). This is a 4 byte, 43.200*20.800 
raster, and I use mapcalc to recategorize it to a one byte, 256 valued 
raster, according to some different categorizing algorithms (essentially 
variations on histogram equalisation). The category boundaries have been 
computed separately; the only thing r.mapcalc has to do is to apply them 
to the input raster. The mapcalc script only consists of a few dozens of 
"if" rules, but these take a very long time to execute (days). My 
impression is that r.mapcalc evaluates every rule for every cell. Does 
anyone know if this is the case, and if so, is there a way to stop 
evaluation after a match has been found (something like an "else" 
statement)?

Jan

Jan Hartmann wrote:
> 
> 
> Glynn Clements wrote:
> 
>>
>> I don't know; I suggest re-running "make" and "make install".
>>
> 
> Yes, now it runs. Thanks.
> 
> Jan
> 
> 

Jan Hartmann
Department of Geography
University of Amsterdam