[R-sig-Geo] polygons to grid?

[Barry Rowlingson]

On Sat, Nov 21, 2009 at 1:20 PM, Agustin Lobo <alobolistas at gmail.com> wrote:
> Hi?
>
> Is it possible to perform a vector to raster conversion in R,
> from SpatialPolygonsDataFrame to a SpatialGrid (providing the final
> resolution?

 If what you want is a raster grid storing the value of some attribute
of polygons sampled at a grid of locations, see help(overlay) and
help("overlay-methods") in package sp. Note the complications that can
happen if your polygons overlap.

 Another possibility is simply to plot your polygons to a png device
with no margins or axes or other decorations. I'd call this a
different class of vector-raster conversion, and might be what you
need if you want a raster representation of the outline of your
polygons. You'd then need to read in the png and set coordinates with
the other various raster handling functions.

Barry