[GRASS-user] Problem with r. mapcalc

[Maris Nartiss]

Hello Giuseppe,
I am too lazy to calculate binary representation of your numbers, but
your suspicion of insufficient precision of float seems to be spot-on.

If output is set to DCELL, then the result is exactly as you would
expect. Try yourself:
r.mapcalc  expression="output=basin - 241981407231.0"
Range of data:    min = 1  max = 3024784769025

Māris.