[R-sig-Geo] Subsetting a spatial grid

[Dylan Beaudette]

On Wednesday 10 December 2008, Rob Robinson wrote:
> Help - please! :-)
>  I have what I thought was a really simple problem. I have a raster image
> of satellite data from which I would like to extract an arbitrary (but
> simple rectangular) portion for subsequent analysis (which I'll need to do
> for many images). I have the data as a (projected) SpatialGridDataFrame and
> have tried two approaches: create a SpatialPolygon and overlay it (but I
> don't think overlay does what I would like it to do), or access the coords
> slot of the data set and pick those within the range. I haven't been able
> to get either to work - presumably because my R is not good enough! It
> seems a fairly common task, but I haven't yet stumbled across an FAQ or
> page in ASDAR which seems to help. Any pointers anyone?
> Many thanks for any help
> Cheers
> rob

Not sure how to do this in R, but gdal_translate can do this for you on the 
command line. you will need a working GDAL install.

Cheers,

Dylan

>
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-- 
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341