It seems to me that you need "overlay" in the sp package. Essentially it allows you to determine which points (sampling stations) are in which polygons (watersheds). Robert
On Thu, Jan 28, 2010 at 8:58 PM, <musc...@comcast.net> wrote: > > Being new to spatial analysis I don't have the right vocabulary. I have > purchased the book applied spatial data analysis in r, but not received yet. > > I have a set of irregularly spaced points (utmx,utmy) where animals were > sampled. So for each point I have a location and a species count. There is a > spatial pattern in the data (for richness) - it is not just random. I have > used a gam from mgcv to model the data. I would like to overlay a shapefile > of polygons (watersheds) over the point data and in the end estimate the > expected number of species in a watershed. For example if a watershed > overlayed two bands of species richness one for a richness of 5 and one for a > richness of 6 and each were equally represented in the watershed the expected > number for a point in the watershed would be 5.5. Can someone point me in the > right direction or provide terminology and/or packages that may do this. > thank you. > > [[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
