> Which sp objects does quadsegs argument in gBuffer affect (or rather, which > it does not)? Based on my experiments, SpatialPoints -> SpatialPolygons is > not affected. I use SpatialPoints to draw circles (see below) and I figured > that specifying the quadsegs would alter the "roughness" of the circle > generated (which is now SpatialPolygons). This doesn't seem to be the case. > Can someone expand on this? > > sap <- gBuffer(spgeom = sap, width = 500, quadsegs = 5) > nrow(sap@polygons[[1]]@Polygons[[1]]@coords) #always the same, irrespective > of quadsegs
This should not be happening and when I run similar code I do get a difference in the number of coordinates as expected using the most current version of rgeos 0.1-4: > x=SpatialPoints(cbind(x=1,y=1)) > z1=gBuffer(x,quadsegs=10) > z2=gBuffer(x,quadsegs=5) > nrow(z1@polygons[[1]]@Polygons[[1]]@coords) [1] 41 > nrow(z2@polygons[[1]]@Polygons[[1]]@coords) [1] 21 There may be some weirdness with your initial SpatialPoints object that is causing this but I don't have a plausible theory as to why. Try the above code and see if you still have the problem and double check that your rgeos is up to date. -Colin _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
