[GRASS-user] Fwd: calculate values of an attribute table column

[Moritz Lennert]

On 21/10/08 14:37, G. Allegri wrote:
> Are you sure Moritz that in qcolumn you can use multiple columns? If
> it's true I've always excluded it because of a bug in my Grass! :)

I only have grass7 installed at the moment, but there it works (using 
the North Carolina demo data):

g.copy vect=censusblk_swwake,myblocks
v.db.addcol myblocks col='result double precision'
v.db.update myblocks col=result qcol='P65_OLDER/TOTAL_POP' 
where="TOTAL_POP>0"
v.db.select myblocks col=P65_OLDER,TOTAL_POP,result


Moritz