[R] Coloring counties on a full US map based on a certain criterion

[Dimitri Liakhovitski]

Dear Rers,

is there a way to color counties on a full US map based on a criterion
one establishes (i.e., all counties I assign the same number should be
the same color)?
I explored a bit and looks like the package "maps" might be of help.
library(maps)
One could get a map of the US: map('usa')
One could get countries within a US state: map('county', 'iowa', fill
= TRUE, col = palette())

Would it be possible to read in a file with counties and their
assignments (some counties have a 1, some counties have a 2, etc.) and
then have one map of the US with counties colored based on their
assignment?

Thanks a lot for any hint!


-- 
Dimitri Liakhovitski