[R-sig-Geo] How to extract part of Map object using maptools

[Barry Rowlingson]

Edzer J. Pebesma wrote:


> but the more I think about it, the less I like it: expanded bounding boxes
> do not describe the data in the object, and probably are only of use to
> extend the plotting area -- a trick. For that purpose we'd better pass a
> bbox to generic plotting functions, as in
> 
> plot(europe, bbox=bbox(world))

   plot((1:10)[1:5]) doesn't give you a bounds from 1 to 10, so I dont 
see why the bounds of a subsetted map should be those of the parent.

  A subset of a map object is a map in its own right, and if that means 
recalculating its bounding box, then you better recalculate it!

Baz