Mel, Sorry, your pseudo-code:
raster::extract(udel, admin, fun=mean, na.rm=T, small=T, weights = TRUE) Chris On Tue, Oct 18, 2016 at 6:10 PM, chris english < englishchristoph...@gmail.com> wrote: > Mel, > > Looking at detail in cjg.png the northmost missing data island shows > approx 20-25 in Southern three quarters and 0-5 the small North at tip of > island. Directly above this 0-5 another coastal 0-5. > If a substantial east-west scarp bisected the island it might explain. I > would otherwise expect a very slight mismatch in projection, a thing I > often have problems with. > > Though reading raster::extract it looks like you want to employ the > weights are if your polys are relatively smaller than your cells. > > HTH > Chris > > On Oct 18, 2016 4:35 PM, "Bacou, Melanie" <m...@mbacou.com> wrote: > >> Hi, >> I'm summarizing biophysical rasters (UDEL precipitation and temperature) >> across administrative units for countries in Africa using (pseudo code): >> >> raster::extract(udel, admin, fun=mean, na.rm=T, small=T) >> >> Out of the 756 units I need data for, extract() fails to return means for >> a few coastal units (in red on the maps below) even though the rasters show >> data at these locations. >> >> Is there a particular reason why this might happen? Shall I look for >> possible geometry errors in my source shapefiles, or could there be another >> reason? >> >> Maps here: >> https://dl.dropboxusercontent.com/u/30925475/eclgcdmhapfplaml.png >> https://dl.dropboxusercontent.com/u/30925475/lmkgmdoohpmhdcjg.png >> >> Thanks for any tip. --Mel. >> >> _______________________________________________ >> R-sig-Geo mailing list >> R-sig-Geo@r-project.org >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >> > [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
