r.mapcalc and NULL

[Agustin Lobo]

How can I represent NULL values in r.mapcalc?

I mean, doing something like this:

 r.mapcalc "test3 = if(test == NULL)"

Is there any doc explaining the use of the NULL values
in grass?

Thanks

Agus

Dr. Agustin Lobo
Instituto de Ciencias de la Tierra (CSIC)
Lluis Sole Sabaris s/n
08028 Barcelona SPAIN
tel 34 93409 5410
fax 34 93411 0012
alobo at ija.csic.es
http://pangea.ija.csic.es/alobo