Re: [igraph] random graph

[Csardi Gabor]

Thiago,

why do you expect that ALL edges will be different in the 
randomized graph? Some edges will be the same, just by chance, and 
especially the big hubs have a good chance for this.

Gabor

On Thu, Aug 21, 2008 at 10:35:38AM -0400, Thiago M. Venancio wrote:
> Hi Guys...
> I have tested the suggestions, but am experiencing a problem here. By simple
> rewiring I can reach up to 85% of rewiring, what seems pretty good. However,
> the 15% remaining edges are retained in a large fraction of the random
> graphs I created. Thus, I think they are not that random...
> I have also tested the method Gabor suggested, but the problem persists.
> Typically the problematic edges are involving one of the large hubs of the
> graph.
> Any clues ?
> Thanks.
> Thiago
> 
> On Thu, Aug 14, 2008 at 3:09 AM, Csardi Gabor <address@hidden> wrote:
> 
> > Hmmm, degree.sequence.game is another option, especially
> > in the new 0.5.1 R package, with method="vl". It is perhaps
> > faster for larger graphs and it is known to be a uniform
> > sampler.
> >
> > Gabor
> >
> > On Wed, Aug 13, 2008 at 07:55:38PM +0100, Tamas Nepusz wrote:
> > > Hi Thiago,
> > >
> > > >Is it possible to make an undirected random graph from a reference
> > > >one, keeping the same degree for each vertex ?
> > > Yes, it is. In C, see igraph_rewire. In Python, it's Graph.rewire()
> > > and I think it's simply called "rewire" in R.
> > >
> > > --
> > > Tamas
> > >
> > >
> > >
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> >
> > --
> > Csardi Gabor <address@hidden>    MTA RMKI, ELTE TTK
> >
> >
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> >
> 
> 
> 
> -- 
> ========================
> Thiago Motta Venancio, M.Sc., PhD
> http://tmvenancio.googlepages.com
> ========================

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-- 
Csardi Gabor <address@hidden>    MTA RMKI, ELTE TTK