GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  -  TEXT::NSP::MEASURES::3D::MI::PMI (3)

.ds Aq ’

NAME

Text::NSP::Measures::3D::MI::pmi - Perl module that implements Pointwise
Mutual Information for trigrams.

CONTENTS

SYNOPSIS

Basic Usage



  use Text::NSP::Measures::3D::MI::pmi;

  $pmi_value = calculateStatistic( n111=>10,
                                  n1pp=>40,
                                  np1p=>45,
                                  npp1=>42,
                                  n11p=>20,
                                  n1p1=>23,
                                  np11=>21,
                                  nppp=>100);

  if( ($errorCode = getErrorCode()))
  {
    print STDERR $erroCode." - ".getErrorMessage()."\n";
  }
  else
  {
    print getStatisticName."value for bigram is ".$pmi_value."\n";
  }



DESCRIPTION

The expected values for the internal cells are calculated by taking the product of their associated marginals and dividing by the sample size, for example:



            n1pp * np1p * npp1
   m111=   --------------------
              nppp * nppp



Pointwise Mutual Information (pmi) is defined as the log of the devitation between the observed frequency of a trigram (n111) and the probability of that trigram if it were independent (m111).



 PMI =   log (n111/m111)



    Methods

initializeStatistic() -Initialization of the pmi_exp parameter if required INPUT PARAMS : none

RETURN VALUES : none

calculateStatistic() - This method calculates the pmi value INPUT PARAMS : $count_values .. Reference of a hash containing
the count values computed by the
count.pl program.

RETURN VALUES : $pmi .. PMI value for this trigram.

getStatisticName() - Returns the name of this statistic INPUT PARAMS : none

RETURN VALUES : $name .. Name of the measure.

AUTHOR

Ted Pedersen, University of Minnesota Duluth
<tpederse@d.umn.edu>

Satanjeev Banerjee, Carnegie Mellon University
<satanjeev@cmu.edu>

Amruta Purandare, University of Pittsburgh
<amruta@cs.pitt.edu>

Bridget Thomson-McInnes, University of Minnesota Twin Cities
<bthompson@d.umn.edu>

Saiyam Kohli, University of Minnesota Duluth
<kohli003@d.umn.edu>

HISTORY

Last updated: $Id: pmi.pm,v 1.9 2009/11/03 14:53:55 tpederse Exp $

BUGS

SEE ALSO



  @inproceedings{ church89word,
      author = {Kenneth W. Church and Patrick Hanks},
      title = {Word association norms, mutual information, and Lexicography},
      booktitle = {Proceedings of the 27th. Annual Meeting of the Association for Computational Linguistics},
      publisher = {Association for Computational Linguistics},
      address = {Vancouver, B.C.},
      pages = {76--83},
      year = {1989},
      url = L<http://acl.ldc.upenn.edu/J/J90/J90-1003.pdf> }



<http://groups.yahoo.com/group/ngram/>

<http://www.d.umn.edu/~tpederse/nsp.html>

COPYRIGHT

Copyright (C) 2000-2006, Ted Pedersen, Satanjeev Banerjee, Amruta Purandare, Bridget Thomson-McInnes and Saiyam Kohli

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to



    The Free Software Foundation, Inc.,
    59 Temple Place - Suite 330,
    Boston, MA  02111-1307, USA.



Note: a copy of the GNU General Public License is available on the web at <http://www.gnu.org/licenses/gpl.txt> and is included in this distribution as GPL.txt.

Search for    or go to Top of page |  Section 3 |  Main Index


perl v5.20.3 TEXT::NSP::MEASURES::3D::MI::PMI (3) 2009-11-03

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.