AND - is there a general function in R available to map demographic data between two boundary systems OR - is there an efficient R function that can determine the amount of area overlap between two general polygons (beyond gpclib)
I am willing to share developed code for this problem (that's why I would prefer gpl code over gpclib, which is not really free)
Thanks for any help
There is pretty cool polygon intersection algorithm available at:
http://davis.wpi.edu/~matt/courses/clipping/4th.html
with the code at:
http://davis.wpi.edu/~matt/courses/clipping/code.html
You can pick up the paper the code is based on from kai hormann's home page (currently):
http://vcg.isti.cnr.it/~hormann/
The only problem with the algorithm is that it doesn't handle holes, but for area computations you could just join the holes to the boundary.
-- Ross Ihaka Email: [EMAIL PROTECTED] Department of Statistics Phone: (64-9) 373-7599 x 85054 University of Auckland Fax: (64-9) 373-7018 Private Bag 92019, Auckland New Zealand
______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
