maptools: appending data to SpatialPolygonsDataFrame

Dear all,

I am just starting to use the library maptools. Specifically, I want to
use it as a quick way to map results from various multivariate analyses
(e.g. cluster analyses) directly in R.
I encountered problems appending newly generated data (cluster
memberships) to the SpatialPolygonsDataFrame object. Unfortunately, the
documentation is not really helpful.

But I am sure that this is an easy question for you.

Thanks in advance,

Holger


The code so far:

my.polys <- readShapePoly("Z://mypoly.shp",IDvar="ID",verbose=T)
plot(my.polys)