----Messaggio originale----
Da: Roger.Bivand at nhh.no
Data: 03/04/2009 21.40
A: "milton ruser"<milton.ruser at gmail.com>
Cc: <r-sig-geo at stat.math.ethz.ch>
Ogg: Re: [R-sig-Geo] rasterize shape file and output as .img
On Fri, 3 Apr 2009, milton ruser wrote:
Dear all,
I have a set of shapefile and I need rasterized it using a collumn called
ClassCover,
and with the resolution of 30 meters. How can I do this on R?
Use bbox() of the SpatialPolygonDataFrame to find the extent. Create a
GridTopology object, and overlay the polygons - possibly just with
ClassCover - and the SpatialGrid built with the GridTopology object. This
should yield a SpatialGridDataFrame with a single band, with NAs outside
the polygons, and the polygon column values for raster cells where their
centres fall inside the polygons.
Another thing is that I need to output the raster as IMG (erdas/arcgis)
format.
writeGDAL in rgdal.
Hope this helps,
Roger
Any help are welcome.
Best wishes,
milton
Brasil/Toronto
require(maptools)
require(sp)
require(rgdal)
todos<-readShapePoly("myshape.shp")
sessionInfo()
R version 2.9.0 alpha (2009-03-26 r48224)
i386-pc-mingw32
locale:
LC_COLLATE=English_Canada.1252;LC_CTYPE=English_Canada.1252;
LC_MONETARY=English_Canada.1252;LC_NUMERIC=C;LC_TIME=English_Canada.1252
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] rgdal_0.6-7 maptools_0.7-20 sp_0.9-32 foreign_0.8-34
loaded via a namespace (and not attached):
[1] grid_2.9.0 lattice_0.17-20
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