^MML^
^Structured^
^Mixtures^
>factorsnob>
SNOB is written in Fortran 77, and more recently C,
and is available from:
[Snob][2003],
[Snob][2001].
(NB. So called "vanilla" Snob only implements
multi state and normal dist'ns as of '04.)

SNOB.
SNOB is a computer program for
unsupervised classification of multivariate data.
The classification problem is sometimes called
clustering, mixture modelling or numerical taxonomy.
SNOB uses the Minimum [MessageDescription] Length [Encoding]
(MMLMDL)
principle to decide upon the best classification of the data.
MML encoding is a realisation of
Ockham's razor.
SNOB is very efficient and can classify many tens of thousands
of "things" quickly,
where each thing can have tens of "attributes" (variables).
An attribute can be
continuous
(realvalued) or
discrete
(multistate).
A "class" is defined by distributions on one or more,
but not necessarily all, attributes.
The number of classes, the classes, their
defining attributes and distributions, and class memberships
are all inferred by SNOB.
Selected Bibliography:
 C. S. Wallace. Vanilla Snob. 2002
[www]['02].
 C. S. Wallace.
Classification by MinimumMessageLength Inference.
Advances in Computing and Information  ICCI '90.
Springer Verlag LNCS 468 pp.7281 1990.
 C. S. Wallace & P. R. Freeman.
Estimation and Inference by Compact Encoding.
J. R. Stat. Soc. B 49 pp.240265 1987
 D. M. Boulton & C. S. Wallace.
An Information Measure for Hierarchic Classification.
Computer Journal 16(3) pp.254261 1973.
 D. M. Boulton & C. S. Wallace.
A Program for Numerical Classification.
Computer Journal 13(1) pp.6369 1970.
 C. S. Wallace & D. M. Boulton.
An Information Measure for Classification.
Computer Journal 11 pp.185195 1968.
 L. Allison.
Models for machine learning and data mining in functional programming.
J. Functional Programming,
15(1), pp.1532, Jan. 2005.
 Includes the source code of the
core expectationmaximization (EM) algorithm for clustering.
Also see [I.I.].
Also see
[Inductive Inference]
for more on mixture models,
[CSW's publications],
and search for `Snob' in the [bibliography].
©
L. Allison / 1994, 1999, 2000, 2001, 2002, 2003, 2005
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