[R-sig-Geo] plot methods in sp

[Patrick Giraudoux]

Dear listers,

I am working since a while with the sp package and still wonder how the 
plot methods are managed with sp spatial objects. For instance, 
SpatialPolygonsDataFrame objects have obviously a plot method. However 
it cannot be found in the list provided by methods(plot) . Furthermore 
?plot.SpatialPolygonsDataFrame, nor ?plot.SpatialPolygons, etc.. provide 
a help, though the lattice function spplot is adequately documented.

On the other hand, plot(myobject, border="grey"), with myobject a 
SpatialPolygonsDataframe is well interpreted and recalls the syntax of 
plot.polylist of matools (though myobject is far from being a polylist...).

Can anybody (especially the package's authors...) comment on this? Where 
a help with the list of the plot function arguments can be found?

Thanks for any hint,

Patrick