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## Re: [igraph] how to add disconnected nodes to a graph?

 From: Ahmed Abdeen Hamed Subject: Re: [igraph] how to add disconnected nodes to a graph? Date: Sat, 7 Dec 2013 21:41:02 -0500

Thanks again! It does make sense but I think it gives more credit to the disconnected nodes that it really should. If we comparing the closeness of a connected node to another that's disconnected, it will not be a fair comparison. Is it acceptable to multiply the returned closeness value by a very small number as a workaround?

CONST = 9999999999.99
finalCloseness = igraphCloseness * (1/CONST)

Does this sound right?

-Ahmed

On Fri, Dec 6, 2013 at 5:24 PM, Tamás Nepusz wrote:
> I misspoke, I meant closeness

Closeness is different; an isolated vertex will have a closeness centrality of 1/n where n is the number of vertices. This is due to how igraph defines closeness centrality for disconnected graphs: when two nodes are disconnected, igraph assumes that their distance is n because we cannot use infinity for obvious reasons, and n is always larger than the longest possible geodesic in a network so it sort of makes sense.

T.