Dear OSGEO list members,
I have installed R-10.1 on windows XP. My problem:
I have a polygon (the border of the Zuiderzee (=IJmeer?!) in the 
Netherlands) and a SpatialPixelsDataFrame, containing genetic similarities 
among watersnakes across geography, bound to the convex hull curve of the 
sampling coordinates, around the Zuidersee). What I want, is to cut off the 
spatial grid by the edges of the Zuiderzee.
What I so far only got by trying the overlay function is:
###
zuiderzee_union # the polygon of the Zuiderzee
rinsl.SPix.clus.clip # the SpatialPixelDataFrame
sel=!is.na(overlay(rinsl.SPix.clus.clip, zuiderzee_union))
###  A  %over%  B
rinsl.SPix.clus.union.clip <- rinsl.SPix.clus.clip[sel,]
##
This operation cuts out the area, which lies in the Zuiderzee - but I just 
need the inverse (I assume acc. to the A and (not B) boolean opeation),  
the area which is outside the Zuiderzee.

Any help is much apprecited!
Many Thanks in advance!


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Axel Hille (Dr. rer. nat.)
population genetic and geography
D-33605 Bielefeld
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-- 
Dr. rer. nat. Axel Hille
Diplom-Biologe

Schon gehört? GMX hat einen genialen Phishing-Filter in die


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