plot a variable in a SpatialPolygons object

Dear all,
sorry my question seems to me quite basic and perhaps is already posted 
but at a first sight I did not find it. Basically I have a map of 
contiguous areas in the form of a SpatialPolygons object. In all areas I 
need to display the value of a binary value (e.g. to color the areas 
corresponding to value 1). I have to say in a guide to the package 
"spdep" I found the code to do a map (it was a map of probabilities 
buillt by using plot coomand after having used probmap command), but in 
that case the plot is done starting from an object of class polylist if 
I say well. Instead I need to do a plot starting from a SpatialPolygons 
object because I do not have the map in other formats.
I'm planning to update the now very obsolete vignette in spdep soon. The 
easiest way to plot a variable from a SpatialPolygonsDataFrame object is 
the spplot method in the sp package (which spdep loads). Just try:

spplot(my_SpolDF, "myvar")

for a first cut.

Base graphics methods, such as plot(), are also available. The best online 
guide may be one of the units at:

http://www.bias-project.org.uk/ASDARcourse/

either "Vizualising Spatial Data" for the description, or your choice of 
the worked examples. There are also code examples and figures on the ASDAR 
book website: www.asdar-book.org; though this is still under construction, 
most things are there.

Roger
Moreover, in future I will also need to plot values graduated by colors.

Please, can you help me?
thanks in advance
massimo

Massimo Ventrucci
Ph.D Student in Statistics
Dipartimento di Scienze Statistiche
Universit? degli studi di Bologna
Via Belle Arti 41
40126 Bologna-Italy
_____________________________________

Phone +39(051)264182 (office)
Fax     +39(051)232153
E-mail massimo.ventrucci at unibo.it

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Economic Geography Section, Department of Economics, Norwegian School of
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e-mail: Roger.Bivand at nhh.no

plot a variable in a SpatialPolygons object

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