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 > > *** Want to know about Britain's birds? Try www.bto.org/birdfacts *** > > Dr Rob Robinson, Senior Population Biologist > British Trust for Ornithology, The Nunnery, Thetford, Norfolk, IP24 2PU > Ph: +44 (0)1842 750050 E: [EMAIL PROTECTED] > Fx: +44 (0)1842 750030 W: www.bto.org/cv/rob_robinson.htm > > ==== "How can anyone be enlightened, when truth is so poorly lit" ===== > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Dylan Beaudette Soil Resource Laboratory http://casoilresource.lawr.ucdavis.edu/ University of California at Davis 530.754.7341 _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo