Re: [igraph] python ig.Graph.multilevel_community

[Lucio Floretta]

Hi Tamás,

thank you very much for helping me out and for the effort you put in graph: it 
is a terrific tool!

Best,
Lucio


On Oct 11, 2013, at 11:09 PM, Tamás Nepusz <address@hidden> wrote:

> Hi Lucio,
> 
> Sorry for the late reply. I went back to the revision of the code that was 
> used when igraph 0.6.5 was released and indeed you are right, there is a bug 
> with the weighted multilevel community detection code. I did not notice it 
> because I was accidentally using the development version where this was fixed 
> already; see the following commit:
> 
> https://github.com/igraph/igraph/commit/228dae0f88a22b76efb6bfd6be67e24d3097d376
> 
> You can either apply the patch manually on your copy of igraph's source code 
> and then recompile, get a nightly build from http://code.google.com/p/igraph 
> (and compile it of course), or use a simple hack for the time being. The 
> problem stems from the fact that we accidentally used an integer to store the 
> maximum edge weight instead of a floating-point number, so the maximum weight 
> is rounded down when it is stored in this variable. A workaround is simply to 
> multiply your weights by a large number (say, 1000000) and then round them. I 
> tried it with a multiplicative factor of 1000000 and the result had a 
> modularity of 0.0215057.
> 
> All the best,
> Tamas
> 
> On 8 Oct 2013, at 14:10, Lucio Floretta <address@hidden> wrote:
> 
>> Hi Tamas,
>> 
>> I have run the commands you suggested, but the outcome of len(com1) is 1619 
>> and not 63. 
>> 
>> I am working on a MacBook with Snow Leopard, python 2.6.8 and igraph 0.6.5. 
>> I installed the library and the python module from macports.
>> 
>> Thank you for helping,
>> Lucio Floretta 
>> 
>> 
>