extract polygon
Ross, what you want is subsetting, not extraction. have you tried: newSPDF <- columbus[30,] Reading introductory material such as http://cran.r-project.org/web/packages/sp/vignettes/intro_sp.pdf is also a good way to learn the first steps. Bests,
On 03/29/2013 04:32 PM, Ross Ahmed wrote:
Lets say I have a several polygons stored in a SpatialPolygonsDataFrame
object. Using ?columbus? in maptools as an example:
setwd(system.file("shapes", package="maptools"))
columbus <- readShapeSpatial("columbus.shp?)
I want to extract a polygon 30 from ?columbus?, and assign it to a new
SpatialPolygonsDataFrame object. I?ve tried?
newSPDF <- Polygons(list(columbus at polygons[[30]]), "29?)
?but this didn?t work. How can I do this?
Thanks
Ross
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