Algorithm::ExpectationMaximization is a perl5 module for the
Expectation-Maximization (EM) based clustering of numerical
data in multidimensional spaces.  Since the module is
entirely in Perl (in the sense that it is not a Perl wrapper
around a C library that actually does the clustering), the
code in the module can easily be modified to experiment with
several aspects of the EM algorithm.

This module is not meant for very large datafiles.  Being an
all-Perl implementation, the goal here is not the speed of
execution.  On the contrary, the goal is to make it easy to
experiment with the different facets of the EM algorithm
with regard to its ability to identify the individual
Gaussians in data that can be modeled as a Gaussian mixture.

This module requires the following three modules:

   Math::Random
   Graphics::GnuplotIF
   Math::GSL::Matrix

the first for generating the multivariate random numbers,
the second for the visualization of the clusters, and the
third for access to the Perl wrappers for the matrix
handling portion of the GNU Scientific Library for the
algebraic manipulation of the matrices that are needed for
the covariances of the Gaussians.

For installation, do the usual

    perl Makefile.PL
    make
    make test
    make install

if you have root access.  If not, 

    perl Makefile.PL prefix=/some/other/directory/
    make
    make test
    make install

Contact:

Avinash Kak  

email: kak@purdue.edu

Please place the string "Algorithm EM" in the subject line
if you wish to write to the author.  Any feedback regarding
this module would be highly appreciated.