[GRASS-stats] Specify attribute column in SpatialPolygonsDataFrame when using overlay(grd, polyg)

[Rainer M Krug]

Hi


I have a SpatialGridDataFrame-class (grd) and a
SpatialPolygonsDataFrame (polyg) with more then one attribute columns,
i.e.

names(slot(polyg, "data"))

results in

"a", "b", "c", ... "z"

I want to use overlay to convert polyg into a grid, by assigning the
values of attribute column "d" to the grid.

Is it possible to specify the column name in the following overlay statement:

d <- overlay(grd, polyg)
grd[[1]] <- d

results in the values of the attribute column "d" in grd[[1]]?

Thanks,

Rainer

-- 
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation
Biology, UCT), Dipl. Phys. (Germany)

Centre of Excellence for Invasion Biology
Faculty of Science
Natural Sciences Building
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University of Stellenbosch
Matieland 7602
South Africa