[GRASS-user] How to generate map subsets?

[brendon wolff-piggott]

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"

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)
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