[GRASSLIST:10865] Re: r.mapcalc limited number of input maps?

[Otto Dassau]

Am Freitag, 10. März 2006 00:59 schrieb Glynn Clements:
> Otto Dassau wrote:
> > I would like to add raster map values with r.mapcalc. Does there exist a
> > maximum number of maps to calculate?
>
> AFAIK, there is only GRASS' limit on the maximum number of open maps
> (256). r.mapcalc doesn't have any fixed limits, but the GRASS
> libraries on which it depends might.
>
> > I tried with 8 maps and it works well, but there is a problem when I want
> > to add e.f more than 30 maps.
> >
> > r.mapcalc "newmap = map1+map2+map3+map4+..."
>
> What's the problem, exactly?

Hi Glynn,

I would like to add a number of maps and it doesn't work with r.mapcalc for a 
large number of input maps but with r.series it is ok. The maps are stored in 
a variable $INPUT and it looks like this:

echo "$INPUT"
map1+map2+map3+map4+map5...

the r.mapcalc command is:
r.mapcalc "output.$TIMESTAMP = $INPUT"

r.mapcalc calculates without errors but the resulting map is empty when the 
number of input maps is high. I don't know the exact number of maps, when it 
works and when not. I only tested with 8 and with 30.  8 is fine 30 not.

I just wonder, why and thought there might be a limit of input maps for 
r.mapcalc.

 thanks
   Otto