[R-sig-Geo] RSAGA Vectorizing Grid Classes creates unclosed rings

[manuel.schneider]

Roger Bivand <Roger.Bivand <at> nhh.no> writes:

> 
> On Tue, 11 May 2010, manuel.schneider <at> art.admin.ch wrote:
> 
...
> > Error in is.vector(X) : ring not closed
> 
> http://shapelib.maptools.org/dl/shapefile.pdf
> 
> does specify that a polygon in a shapefile must be closed. You may be able 
> to use readShapePoly(..., force_ring=TRUE) in maptools to work around the 
> problem.
> 
> Roger
> 
> 

As always, your suggestion does the trick. Thanks a lot.
However, still puzzled why it occurs.