border

Good day!
I would like to connect 2,3 or 4 administrative units so as not to have
a common border.

Please see the unionSpatialPolygons() function in maptools.

Note that you (still) need to use the gpclib package to dissolve borders, 
which has a rather non-free licence. If this is a problem, ask again, and 
I'll direct you to the beta rgeos package and forthcoming changes in 
maptools, which will prefer rgeos over gpclib if rgeos is installed.

Hope this helps,

Roger

PS. an informative signature would avoid doubt about licences, because if 
you are in academia, the gpclib licence would possibly be OK (educational 
purposes, hobby, etc.), but if you work in real estate or telecoms, it 
certainly isn't, even just for using gpclib, I'm afraid. This is one of 
the reasons why informative affiliations or signatures help us give 
appropriate advice.

Thanks in advance for your help.
Adam

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