Hi Pete,you get the indices of the points inside the polygons and the associated polygon ID value.
something like clip<- grd[!is.na(overlay(grd, ccShapet)),] should do.Hope this helps, although I did not check the line in particular (just from the top of my head)
Kamran Am 28.10.2010 22:23, schrieb Peter Larson:
Hello all, I have a grid of points and a spatial polygon shape file. I want to clip the grid so that I only have the point which lie within the shapefile. I tried the following code: ## create a grid onto which we will interpolate: ## first get the range in data x.range<- c(37,50) y.range<- c(29,38) ## now expand to a grid with 500 meter spacing: grd<- expand.grid(x=seq(from=x.range[1], to=x.range[2], by=.01), y=seq(from=y.range[1], to=y.range[2], by=.01) ) ## convert to SpatialPixel class coordinates(grd)<- ~ x+y gridded(grd)<- TRUE ## Read in Shapefile ccShapet=readShapePoly('IRQ_adm0') # here cbg00barncnty is an ArcGIS shapefile ## Clip clip<- overlay(grd, ccShapet) #Plot plot(clip) BUT it does not work. I just get a vector of number and NA's, but not the clipped grid. Any ideas? Thanks Pete _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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