How to set the resolution parameter for Louvain modularity in igraph?

Question

is there a way to set the resolution parameter when using the function cluster_louvain to detect communities in igraph for R? It makes a lot of difference for the result, as this parameter is related to the hierarchical dissimilarity between nodes. Thank you.

Meacham

In the current version they added the resolution parameter in the cluster_louvain() function – Ahasuerus

Thank you! I'll take a loot at it. – Meacham

Answer 1

The easiest way to do it is through the resolution package, available in this link https://github.com/analyxcompany/resolution

It is based on this paper http://arxiv.org/pdf/0812.1770.pdf

It pretty much has 2 functions cluster_resolution() and cluster_resolution_RandomOrderFULL(). In both you can state the resolution t and how many repetitions you want rep. And, you can just use the igraph object in the function.

cluster_resolution_RandomOrderFULL(g,t=0.5)
cluster_resolution_RandomOrderFULL(g,rep=20)

NOTE/EDIT: it will not accept signed networks though! I'm trying to either contact the owner of the code or costumize it myself to make it suitable for signed networks.

EDIT2: I was able to translate the function community_louvain.m from the Brain Connectivity Toolbox for Matlab to R.

Here is the github link for the signed_louvain()

you can pretty much just put for ex. signed_louvain(g, gamma = 1, mod = 'modularity') it works with igraph or matrix objects as input. If it has negative values, you have to choose mod = 'neg_sym' or 'neg_asym'.

Aparicio