Re: [igraph] Choosing between different methods of detecting communities

[Gábor Csárdi]

Hi Chen,

On Sat, Sep 29, 2012 at 4:23 AM, 凌琛 <address@hidden> wrote:
> Hi Gabor,
>
> Thanks for your reply.
> I know that the edge weights are used to calculate the shortest paths for
> edge betweenness.
> While I don't know that what the edge weights represent in the library.

there is no semantics forced by igraph. Just like your vertices can
represent anything, your edge weights can represent anything you want,
similarity or capacity or distance, etc.

> Specifically, is it the higher the weight, the longer the edge, or inverse?
> Namely, the edge weight denotes the distance between the connected nodes or
> the similarity between the connected nodes.

Whichever you prefer. But note that shortest.paths() (and similarly
edge betweenness calculation) really calculates shortest weighted
paths, so you might need transform your weights for these functions.

Gabor

> Regards,
> chen
>
> On Wed, Sep 26, 2012 at 9:07 PM, Gábor Csárdi <address@hidden> wrote:
>>
>> Hi,
>>
>> weighted edge-betweenness community detection simply means that
>> weighted paths are considered for calculating the shortest paths in
>> the edge betweenness calculation.
>>
>> Best,
>> Gabor
>>
>> On Wed, Sep 26, 2012 at 6:54 AM, 凌琛 <address@hidden> wrote:
>> > Hi,
>> >
>> > Have you used the Weighted Girvan-Newman community detected algorithm in
>> > the
>> > library to detect community?
>> > I am not sure what the edge weight represent in this algorithm in
>> > Igraph,
>> > similarity or distance?
>> >
>> > Thanks,
>> > chen
>> >
>> > On Wed, Sep 26, 2012 at 6:48 PM, Minh Nguyen <address@hidden>
>> > wrote:
>> >>
>> >> Hi,
>> >>
>> >> On Wed, Sep 26, 2012 at 8:21 PM, Roey Angel <address@hidden>
>> >> wrote:
>> >> > I was wondering if there's a way to choose between the methods,
>> >> > either
>> >> > by
>> >> > experience (e.g. 'method x typically gives best results) or with some
>> >> > statistical test.
>> >>
>> >> There is a general class of statistical tests called the significance
>> >> of community.  The relevant ideas and techniques can be found in the
>> >> following papers.
>> >>
>> >> http://dx.doi.org/10.1371/journal.pone.0033721
>> >> http://dx.doi.org/10.1103/PhysRevE.82.066106
>> >> http://dx.doi.org/10.1103/PhysRevE.81.046110
>> >>
>> >> --
>> >> Regards,
>> >> Minh Van Nguyen
>> >> http://bit.ly/mvngu
>> >>
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>> >
>> >
>> >
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>>
>>
>>
>> --
>> Gabor Csardi <address@hidden>     MTA KFKI RMKI
>>
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-- 
Gabor Csardi <address@hidden>     MTA KFKI RMKI