
>> Dear all,
>> 
>> Any way to get the length of common boundaries shared by neighbouring
>> counties in a map in R?
>> 

Roger Bivand said:

>The short answer is no. The R polygon objects do not have topology. 


Hello, could you expand on what you mean by "topology" in this context?
I assume it means that any area/polygon object in a given set is a
subdivision of the plane - i.e. no "overlaps"?  Since, if that were true
of the dataset then "common shared boundaries" is something that can be
assumed reliably.  

There seems to be a fairly context-reliant use of the word "topology" in
some GIS terminology, and I'm not exactly sure what that is.  (I know a
little bit about the far more abstract usage of the term . . .)

Cheers, Mike.


