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[SOLVED]Geodesic distance calculation

PostPosted: Tue Feb 26, 2013 5:25 pm
by Luca
Hi all,
I'm struggling to find a way to measure the distances among many polygons in a vector map, the measure need to be taken between the boundaries. I had a look to Rgeos manual and seems that gDistance could solve my problem. My only concern is if gDistance calculate an euclidean distance or a geodetic distance. I mean, is the distance corrected for the projection used? If yes, whatever projection is fine?
Thank you

Luca

Re: Geodesic distance calculation

PostPosted: Wed Feb 27, 2013 1:29 am
by Didier Renard
Hi

I am not sure you considered the correct forum.
The function gDistance is not part of the RGeoS package.
Nevertheless the problem seems interesting and could be coded if better specifications were given.
What is the dimension of the space in which you consider the problem (dimension 2, I suppose).
What are the average number of polygons that you consider? Why are you mentioning a projection
(for my point of view, this distance should be euclidean in the projected space, whatever the projection)...

Cheers

Re: Geodesic distance calculation

PostPosted: Wed Feb 27, 2013 9:21 am
by Luca
Hi Didier,
you are right, I mixed up RGeos with rgeos package from Cran.... I didn't know they were two distinct packages.
Thank you anyway,
Luca