[GRASS-user] How to generate map subsets?

[Markus Neteler]

On Thu, Oct 9, 2008 at 12:01 PM, brendon wolff-piggott
<mytekmail at gmail.com> wrote:
> Hi all
>
> I am new to GRASS (but not GIS), and am sitting with the latest edition of
> the "Open Source GIS" book in the evenings.  I have a simple problem with
> subsetting a large raster file.
>
> I have SRTM data for a large area (1.9GB), and need to extract a subset of
> the data.  I save a region ("ecoast") for the area I want to extract, load
> it and then use  r.mapcalc to create a subarea but there is an error and no
> output raster is created.
>
> I am typing the commands in a GRASS shell called from the GRASS tools menu,
> and attach my steps following p91 of the book.  Any suggestions appreciated!
>
> Thanks
> Brendon Wolff-Piggott
>
> user at USER-5F22862413 /c/documents and settings/user/grassdata/rsa/geographic
> $ g.region "region=ecoast"

Please post

g.region region=ecoast -p

to understand at which resolution you create the new map (if not the
original res.).

> user at USER-5F22862413 /c/documents and settings/user/grassdata/rsa/geographic
> $ r.mapcalc "srtm_ecoast=srtm_rsa"
>
> GRASS_INFO_ERROR(804,1): Unable to close raster map
> GRASS_INFO_END(804,1)

possilby you have nanometer resolution and try to generate a XXGB file?
Disk full?

Markus