Re: [igraph] Negative eigenvalue centrality

[Gábor Csárdi]

Mike,

you can try to increase the 'ncv' parameter as well, and/or 'nev'.

Sorry, this is a bit of a trial-and-error method for me as well, I
just cannot make ARPACK work properly for all graphs. I guess this is
the price you pay for the speed. I mean you have a fast numeric method
that is fine most of the time, but it fails sometimes.

Gabor

On Mon, May 3, 2010 at 2:18 AM, Michael Ewens <address@hidden> wrote:
> I have encountered this bug:
>
> http://lists.gnu.org/archive/html/igraph-help/2009-11/msg00045.html
>
> where the output of evcent(g)$vector is in [-1,1].  When I run a similar
> centrality measure like authority.score(g)$vector, the results are all
> non-negative.  I tried the suggestion in the above thread to no avail: I
> still get values in -1 to 1.  Any other suggestions?
>
> Mike
>
>
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-- 
Gabor Csardi <address@hidden>     UNIL DGM