Re: [igraph] Community in networks with many nodes but low link-density

[Charles Novaes de Santana]

Hi Gábor,

Actually the walktrap error is about the isolated vertices, as you
say. That is the message I got:

> net<-read.graph("./allnetwork.net",format="pajek")
> comm<-walktrap.community(net)
Error in walktrap.community(net) :
  At walktrap.cpp:140 : isolated vertex found in graph, Invalid value
Calls: walktrap.community -> .Call
Execution halted

Thanks again for your suggestions!

Best,

Charles

On Thu, Nov 1, 2012 at 6:01 AM, Gábor Csárdi <address@hidden> wrote:
> On Thu, Nov 1, 2012 at 12:44 AM, Charles Novaes de Santana
> <address@hidden> wrote:
> [...]
>> Yes, I thought this segfault was due to a resource limitation of my
>> machine (a pc with 4Gb of RAM). I am using igraph-0.6 and that was the
>> message I got:
>>
>>> net<-read.graph("./network.net",format="pajek")
>>> comm<-fastgreedy.community(net)
>
> I see. I tried this on various graphs, and it indeed fails if you have
> loop edges in the graph. You can check for this with any(is.loop(net))
> and remove them with simplify(). I remember fixing this issue with
> loop edges some time ago, it seems that it crept back.
>
> I cannot make walktrap to segfault, but it gives an error message
> about isolated vertices. This was already fixed in our development
> version. Did you get this error message as well?
>
> Thanks, Best,
> Gabor
>
> [...]
>
> _______________________________________________
> igraph-help mailing list
> address@hidden
> https://lists.nongnu.org/mailman/listinfo/igraph-help



-- 
Um axé! :)

--
Charles Novaes de Santana
http://www.imedea.uib-csic.es/~charles
PhD student - Global Change
Laboratorio Internacional de Cambio Global
Department of Global Change Research
Instituto Mediterráneo de Estudios Avanzados(CSIC/UIB)
Calle Miquel Marques 21, 07190
Esporles - Islas Baleares - España

Office phone - +34 971 610 896
Cell phone - +34 660 207 940