Roman, Perhaps you can make a RasterLayer with the cell numbers and then use xyValues with a buffer
r <- raster(original.raser) r[] <- 1:ncell(r) xyValues(r, points, buffer=?) Robert On Wed, Jun 23, 2010 at 7:02 AM, Roman Luštrik <roman.lust...@gmail.com> wrote: > Dear list, > > I'm trying to find cells in a RasterLayer object. Specifically, I'm trying > to find all cells within a radius from a pre-defined point. When I have cell > numbers or coordinates, I can calculate their distance from the > aforementioned pre-defined point. > So far, I've been overlaying a polygon and extracting cell numbers with > polygonValues(), however, this method seems to be somewhat slow (especially > on larger rasters). I've benchmarked it and it is approximately as fast as > if I used distanceFromPoints(), which calculates distances for all cells in > a raster. Is there a faster way of finding these cells? > > Cheers, > Roman > > > -- > In God we trust, all others bring data. > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo