Re: [igraph] closeness and average path length in terms of the harmonic

On 6 March 2013 16:14, Bob Pap <address@hidden> wrote:

Hi Gabor,

Sorry I only come back to you only now. shortest.paths does not seem to indicate the vertices that have been traversed in the shortest paths - just a matrix of those shortest paths. Accordingly, calculating closeness in terms of the harmonic mean distance between vertices (only of of shortest paths passing through a desired vertix!) is not possible this way. Alas, it is, in fact not evident to a non-programmer how to select the shortest paths going though i and then return the harmonic mean of these shortest paths, for all i.

Having looked at closeness(), is seems that closeness is currently done as:

res <- .Call("R_igraph_closeness", graph, vids - 1, mode, weights, PACKAGE = "igraph")
How do I learn more of what is being done by this function? Many thanks.

B.

On 30 November 2012 13:28, Bob Pap <address@hidden> wrote:

Many thanks, I will give it a try.

On 29 November 2012 17:25, Gábor Csárdi <address@hidden> wrote:

Then you can just call shortest.path() (or the equivalent in Python), and work from its output.

G.

On Thu, Nov 29, 2012 at 11:22 AM, Bob Pap <address@hidden> wrote:

instead of (1/sum(distances over i)) you do (sum(1/distances) over i minus the vertix of reference) (for which 1/d would be infinite).
Kind regards,
Bob

On 29 November 2012 16:11, Gábor Csárdi <address@hidden> wrote:
Hi Bob,

What exactly is the harmonic distance between vertices? Sorry, I don't have Newman's book at hand....

G.

On Tue, Nov 27, 2012 at 5:42 AM, Bob Pap <address@hidden> wrote:

Dear all,

closeness and average path length functions in igraph are not defined in terms of the harmonic distance between vertices (and no option exists in version 0.6). Any suggestion on how to implement within igraph this conceptually interesting and straight-forward modification (see for instance Newman's Network book on pages 184 and 185) would be very appreciated - essentially sums are slightly different and over vertices not including the reference one.

Kind regards,
Bob

_______________________________________________
igraph-help mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/igraph-help

--
Gabor Csardi <address@hidden> MTA KFKI RMKI

_______________________________________________
igraph-help mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/igraph-help

_______________________________________________
igraph-help mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/igraph-help

--
Gabor Csardi <address@hidden> MTA KFKI RMKI

_______________________________________________
igraph-help mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/igraph-help

--
Kindly,
Bob Pap

Kindly,

Bob Pap

From:	Bob Pap
Subject:	Re: [igraph] closeness and average path length in terms of the harmonic distance between vertices
Date:	Wed, 6 Mar 2013 17:16:27 +0100