[R-sig-Geo] How to extract part of Map object using maptools
B.Rowlingson at lancaster.ac.uk
Thu Nov 20 15:26:30 CET 2003
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!
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