GSoC project : K-medoids clustering in Madlib

Hello!

I'm an IT student, and I would like to apply for the 2013 GSoC.
I've been looking at this mailing list for a while now, and I saw a
suggestion for GSoC that particularly interested me: implementing the
K-medoids clustering in Madlib, as it is supposed to be more efficient than
the K-means algorithm.

I didn't know about these algorithms before, but I have documented myself,
and it looks quite interesting to me, and even more as I currently have
lessons (but very very simplified unfortunately).

I've got a few questions:
Won't this be a quite short project? I can't get an idea of how long it
would take me to implement this algorithm in a way that would be usable by
postgresql, but 3 months looks long for this task, doesn't it?

Someone on the IRC channel (can't remember who, sorry) told me it was used
in the KNN index. I guess this is used by pg_trgm, but are there other
modules using it currently?
And could you please give me some links explaining the internals of this
index? I've been through several articles presenting of it, but none very
satisfying.

Thanks a lot in advance!