Re: [igraph] Hierarchical Clustering

[uxzmdlj02]

Two things I can think of:
1) Blockmodeling (simple dendogram based on a distance matrix) is  
available in the 'sna' package for R. (I seem to remember doing this  
once in igraph as well...)
2) Cohesive Blocks are available in igraph for R, and may do what you  
need (as long as your graph isn't too big).

Not sure if these will work, but maybe a start?

Peter

On Jan 3, 2009, at 1:39 PM, Shrijeet Paliwal shrijeet.paliwal-at- 
......... |igraph-help| wrote:

> Gabor,
>
> Thanks for taking time. Input, in my opinion is just one network -  
> weighted
> graph of tags. I am not sure how we can make use of the second  
> network (the
> hierarchy) and how can we come up with it, it was not in my mind.  
> Actually
> coming to think of it this is something which is desired as out put  
> (In a
> way)
>
> A soft clustering? How would you define it?
>
>
> See the attached picture. The tag channel could be present in more  
> than one
> clusters again through a way of hierarchy. Its opposite of flat  
> clustering
> with which we are familiar with - each tag go to one cluster period.
>
> --
> Shrijeet
> to iterate is human,to recurse divine.
>
>
> On Sat, Jan 3, 2009 at 2:17 PM, Gábor Csárdi <address@hidden>  
> wrote:
>
> > Shrijeet, there is no such algorithm in igraph, AFAIK.
> >
> > But I am not completely sure what exactly you want to do. I  
> > understand
> > that the input of your algorithm is 1) a weighted graph of tags and  
> > 2)
> > a hierarchy of tags; basically two separate networks. What would be
> > the output? A soft clustering? How would you define it?
> >
> > Best,
> > Gabor
> >
> > On Sat, Jan 3, 2009 at 7:48 PM, Shrijeet Paliwal
> > <address@hidden> wrote:
> > > Hi Everyone,
> > >
> > > 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.
> > >
> > > Thank you guys.
> > > --
> > > Shrijeet
> > >
> > > _______________________________________________
> > > igraph-help mailing list
> > > address@hidden
> > > http://lists.nongnu.org/mailman/listinfo/igraph-help
> >
> >
> >
> > --
> > Gabor Csardi <address@hidden>     UNIL DGM
> >
> >
> > _______________________________________________
> > igraph-help mailing list
> > address@hidden
> > http://lists.nongnu.org/mailman/listinfo/igraph-help
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