I am working on a project in which I am trying to cluster tags (tags associated with blog posts, images, bookmarked URLs etc.). I have used few implementations in igraph one of them was "igraph_community_fastgreedy" which lets me cluster my weighted graph where nodes are tags and edges are similarity measure between two tags.
The output we get using these approaches in hard clusters where a tag will appear in one and only one cluster. Now I have a situation where I want to produce a hierarchical clustering where some dominant tags are at higher levels in hierarchy and hence appaear in one or more clusters where as specific and less generic tags are fal leaves which shall appera in just one cluster.
Is there any algorithm in igraph library which you think might lead me some where? Any other directions or corrections in the way I have framed my question will be deeply appreciated.