Subject: Re: CCL:STATS: Wanted: Program to do cluster analysis

From: [email-masked] (David J. States)
Date: Thu, 21 Jul 1994 16:25:44 -0500

|> I have a set of data, basically x vs y, which forms a scatter graph. I would
|> like to analyses the data to see if there is any significant clusters, ie if
|> some of the points all fall within a cluster, and what the probability is
|> that this is a random effect. ...
|> Andy.
|> Structural and Computation Chemistry [email-masked] - JANET.

What you are asking for is actually a quite high level interpretation.
Not only do you want to know if is there a significant clustering of
the data, but also, how many classes there are.  Is there a
classification that describes the data better than lumping everything
together as one class?  This has been addressed in machine learning
where the technique goes by the name "Bayesian Classification".  Peter
Cheeseman ([email-masked]) at the NASA Aimes Research
Center wrote a program, Autoclass, that implements the technique.

You might also contact Lloyd Allison at Monash University and Larry Hunter
at the National Library of Medicine who have done work in related areas.

David States
Institute for Biomedical Computing / Washington University in St. Louis