[R-sig-Geo] Best way to merge selected regions in a map?

[Frosch, Katharina]

Dear all, 

I work with a county map of Germany and have to merge 100 out of 440
counties in total. I tried several ways, using unionSpatialPolygons from
the spgpc package and combine union and append commands from the gpclib
package, but did not succeed. What is the best and most "elegant" way to
do the merging? Especially: Which objects do I have to use (+ how to
keep and to retrieve the ID of the counties without mixing it up). 

Either I do not manage to choose the respective two counties to merge,
or the commands do not correspond to the object I saved the two counties
in. I start with a MIF/MID file of Europe, which I load into R and then
save using writePolyShape. 

Any explanation how to proceed in general would be great. If this kind
of question is not very specific and is covered, more or less, in any
manual, I'd appreciate the link as I guess that I am lacking also some
basics (and the documentation . 

Thanks in advance
Katharina





Katharina Frosch
Rostocker Zentrum
Konrad-Zuse-Str. 1
18057 Rostock
Tel.: (0381) 2081-148
Fax: (0381) 2081-448
Mail: frosch at rostockerzentrum.de 


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