I simply cannot find out the following: I want to repeat a calculation in GRASS GIS several times. Is there a command for r.mapcalc to repeat a calculation x times (similar to this possibility in r.mfilter, for example)....besides listing that step x times in s shell scripts (I use shell).
You can call r.mapcalc in for loop. In shell it could look like this:
X=5 # initialize first map r.mapcalc "old = 10" # loop for I in `seq $X` do r.mapcalc "new = old + 10" --overwrite g.rename rast=new,old --overwrite done
In shell command
seq 5 creates a sequence 1, 2, 3, 4 , 5.
Note that you shouldn't use r.mapcalc like this (read from and write in the same map):
r.mapcalc "old = old + 10" --overwrite