[R-sig-Geo] clipping polygons, overlaying big polygon on polygons

[Roger Bivand]

On Sun, 21 Feb 2010, Markus Loecher wrote:

> Dear all,
> I apologize if this is too simple a question as it does appear to be a basic
> GIS operation but I have not found the appropriate function that performs a
> clipping of polygons into boundaries given by a (larger "outer") polygon. I
> tried overlay() from package sp and clipPolys from package PBSmapping but
> none converted the "inner" polygons into new ones laying inside the
> boundaries given by the outer polygon.

Maybe a basic GIS operation should be done in a GIS? Otherwise, please 
feel free to consult threads on the license problems of gpclib, and about 
the R-forge rgeos package. If you'd like to contribute such an 
intersection (I think you want the intersection between an arbitrary 
SpatialPolygons object and a simple SpatialPolygons object for the outer 
polygon) function tool to rgeos, or at least a sketch of how it might 
work, that would be helpful.

Roger

>
> Any help would be greatly appreciated,
> Thanks,
>
> Markus
>
> 	[[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no