[R-pkgs] hybridHclust (new package)

[Hugh Chipman]

I'd like to announce the availability of a new library for hybrid
hierarchical clustering, "hybridHclust".  The library has been uploaded
to CRAN and is now available.

The library implements a hybrid of top-down and bottom-up hierarchical
clustering.  Along the way, the idea of a "mutual cluster" is developed.
A mutual cluster is a set of observations whose largest within-group
distance is smaller than the distance to the closest point outside the
set.  The hybrid method is a top-down approach that preserves such
mutual clusters.

Mutual clusters are useful in their own right, and have the interesting
property that they cannot be "broken" by many bottom-up methods.  Tools
that graphically integrate mutual clusters into bottom-up methods are
also included in the library.

Lastly, an implementation of Michael Eisen's bottom-up clustering
algorithm is also in the library.

A paper, soon to appear in Biostatistics, describes this work:

Chipman, H., and Tibshirani, R. "Hybrid Hierarchical Clustering with
Applications to Microarray Data", available at
http://ace.acadiau.ca/math/chipmanh/papers/chipman-tibshirani-2003-modif
ied.pdf

There's an online tutorial at
http://ace.acadiau.ca/math/chipmanh/hybridHclust/index.html 

Hugh Chipman and Robert Tibshirani

-- Hugh Chipman
-- Associate Professor and Canada Research Chair in Mathematical
Modelling
-- Department of Mathematics and Statistics, Acadia University
-- Wolfville, Nova Scotia, Canada B4P 2R6
-- (902) 585-1525, Fax: (902) 585-1074
-- http://ace.acadiau.ca/math/chipmanh/homepage.htm