[R-sig-Geo] PPP with latitude/longitude coordinates

[Rolf Turner]

On 01/08/11 10:13, Angelo Moreno wrote:
> Hello somebady could tell me i f I can create a ppp with latitude and
> longitude coordinates...if that's possible how could I do it?. Thanks a lot.

Well, you can *create* a ppp object with latitude and longitude coordinates,
just the same way you create any ppp object.  Not that the observation 
window
must of course be described in the same coordinate system.

The problem is, what do you do with the object after you've created it?  The
tools in spatstat analyze ppp objects using Euclidean distance calculations,
and these are inappropriate for latitude and longitude coordinates.

So far there is no facility in spatstat for calculating/making use of 
the appropriate
``great circle'' distances that should be used with such coordinates.

There may be tools in the "sp" package which could help you to make some
progress.

     cheers,

         Rolf Turner