Newsgroups: sci.math.stat,comp.ai
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!fas-news.harvard.edu!newspump.wustl.edu!news.ecn.bgu.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!ames!kronos.arc.nasa.gov!taylor
From: taylor@kronos.arc.nasa.gov (Will Taylor)
Subject: Version 2.0 of AutoClass C Bayesian Classifier
Message-ID: <1995Jun8.224541.1640@ptolemy-ethernet.arc.nasa.gov>
Followup-To: taylor@ptolemy.arc.nasa.gov (Will Taylor)
Sender: usenet@ptolemy-ethernet.arc.nasa.gov (usenet@ptolemy.arc.nasa.gov)
Nntp-Posting-Host: muir.arc.nasa.gov
Organization: NASA/ARC Computational Sciences Division
Date: Thu, 8 Jun 1995 22:45:41 GMT
Lines: 55

Announcing the release of version 2.0 of AutoClass C, the Bayesian
classifier which seeks a maximum posterior probability classification.

Key features:
 determines the number of classes automatically;
 can use mixed discrete and real valued data;
 can handle missing values;
 processing time is roughly linear in the amount of the data;
 cases have probabilistic class membership;
 allows correlation between attributes within a class; and
 generates reports describing the classes found;

 and now predicts "test" case class memberships from a "training"
 classification.

Inputs consist of a database of attribute vectors (cases), either real
or discrete valued, and a class model.  Default class models are provided.
AutoClass finds the set of classes that is maximally probable with
respect to the data and model.  The output is a set of class descriptions,
and partial membership of the cases in the classes.

Summary of updates since the initial release on 19 April 1995:

   Version: 1.5	   08 May 95    ported to Sun Solaris 2.4; corrected string
                                overwrite problems; compilation of file
        search-control.c is now optimized; & added binary data file input 
        option.

   Version: 2.0	   08 Jun 95    ported to SGI IRIX version 5.2; converted
                                binary i/o from non-standard (open/close/
        read/write) to ANSI (fopen/fclose/fread/fwrite); converted from 
        srand/rand to srand48/lrand48 for random number generation; added
        prediction capability which uses a "training" classification to
        predict probabilistic class membership for the cases of a "test"
        data file; added new ".s-params" parameter "screen_output_p"; added
        output of real and discrete attribute statistics when data base is
        initially read; corrected garbage output when ".r-params" parameter
        "xref_class_report_att_list" contains mixed real and discrete
        attributes; corrected the handling of unknown real values in reports
        output; and corrected an error in function "output_warning_msgs"
        which caused an abort condition.

For information on how to get this public domain software, see the following
WWW page,
   http://ic-www.arc.nasa.gov:
     /ic/projects/bayes-group/group/html/autoclass-c-program.html

or send e-mail to taylor@ptolemy.arc.nasa.gov

<<<------------------------------------------------------------------->>>
-- 
Will Taylor      RECOM Technologies
Computational Sciences Division - Code IC
NASA Ames Research Center - voice:(415)604-3364, fax:(415)604-3594
MS 269-2, Moffett Field, CA 94035-1000  taylor@ptolemy.arc.nasa.gov
