[GRASSLIST:4649] Re: sum in r.mapcalc

[Otto Dassau]

Glynn Clements wrote:
> 
> Martin Wegmann wrote:
> 
> > I want to calculate the average and standard deviation of a image time
> > series. To calculate the average in r.mapcalc is no problem, but how
> > can I calculate s.d.? I couldn't find a sum sign in the manual. Or is
> > there already a command for calcualting s.d. of several images?
> 
> r.mapcalc doesn't include variance or standard deviation functions. It
> doesn't have a variadic "sum" operator either; you would need to write
> it as e.g. "a + b + c".
> --
> Glynn Clements <glynn.clements at virgin.net>

Hi Martin, 

r.univar is a shell script calculating standard deviation from 
r.stats output. Maybe there you find a solution.

  Otto