pmi.pm Version 0.1
Statistical library package to calculate Pointwise Mutual Information. This package should be used with statistic.pl and rank.pl.
Assume that the frequency count data associated with a bigram <word1><word2> is stored in a 2x2 contingency table:
word2 ~word2 word1 n11 n12 | n1p ~word1 n21 n22 | n2p -------------- np1 np2 npp
where n11 is the number of times <word1><word2> occur together, and n12 is the number of times <word1> occurs with some word other than word2, and n1p is the number of times in total that word1 occurs as the first word in a bigram.
Pointwise Mutual Information (pmi) is defined as the log of the devitation between the observed frequency of a bigram (n11) and the probability of that bigram if it were independent (m11).
np1 * n1p m11 = --------- npp PMI = log (n11/m11)
Ted Pedersen <tpederse@d.umn.edu>
Satanjeev Banerjee <banerjee@cs.cmu.edu>
This measure currently only defined for bigram data stored in 2x2 contingency table.
Mailing List: http://groups.yahoo.com/ngram
Copyright 2000-2004 by Ted Pedersen and Satanjeev Banerjee
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.
To install Text::NSP, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Text::NSP
CPAN shell
perl -MCPAN -e shell install Text::NSP
For more information on module installation, please visit the detailed CPAN module installation guide.