[GRASS-user] temporal mapcalc 3hour precipitation to hourly

[Moritz Lennert]

On 02/12/14 13:30, maning sambale wrote:
> Hi,
>
> A have a temporal raster of 3hourly_rainrate.
>> t.rast.list input=3hr_rainrate
> name|mapset|start_time|end_time
> 3hr_rainrate_2014-11-13_0300|PERMANENT|2014-11-13 03:00:00|2014-11-13 06:00:00
> 3hr_rainrate_2014-11-13_0600|PERMANENT|2014-11-13 06:00:00|2014-11-13 09:00:00
>
> The values are the average hourly rainfall at 3hr snapshot.  I want to
> get the total rainfall which is (raster * 3).  Using t.rast.mapcalc, I
> get this error:
>
>> t.rast.mapcalc input=3hr_rainrate output=hourly_rainrate basename=hourly_rainrate expression="(3hr_rainrate) * (3.0)" nprocs=4
> Start temporal sampling
> Start mapcalc computation
> Invalid map <3hr_rainrate_2014>
> Invalid map <13_0300>
> Parse error
> ERROR: parse error
> ...
> ERROR: parse error
> Invalid map <3hr_rainrate_2014>
> Invalid map <13_1200>
> Parse error
> ERROR: parse error
> ERROR: Error while mapcalc computation
>
> I'm using GRASS 7.0.0.  Thanks!

AFAIK, r.mapcalc has difficulties dealing with map names that contain a 
dash in the name as it interprets it as a minus sign.

Try renaming your maps.

Moritz