Re: [igraph] Community detection algorithm for (almost) full weighted graph

[Gábor Csárdi]

On Fri, Oct 24, 2014 at 4:38 PM, Tamas Nepusz <address@hidden> wrote:
>> In this topic? What is best criterio to consider if a network is dense or
>> sparse? I think is not easy to identify this frontier!
>
> The common agreement (at least in "network science") is that if the number of
> edges is a (sub)linear function of the number of nodes in the network, then 
> the
> network is sparse, otherwise it is dense. Or, in other words, the average
> degree of the network should stay roughly constant as the size of the network
> grows to infinity if it is sparse. If you have a nearly complete graph (like
> one constructed from a correlation matrix without any thresholding), then the
> number of edges is roughly |V|^2 so it does not grow linearly if |V| 
> increases,
> therefore the graph is dense.
[...]

Yes, the definition is fine for a model, but what if you have a single
observation? Or even a couple?

Gabor