Text::NSP - Extract collocations and Ngrams from text
use Text::NSP::Measures::2D::MI::ll;
my $npp = 60; my $n1p = 20; my $np1 = 20; my $n11 = 10;
$ll_value = calculateStatistic( n11=>$n11,
n1p=>$n1p,
np1=>$np1,
npp=>$npp);
if( ($errorCode = getErrorCode()))
{
print STDERR $errorCode." - ".getErrorMessage()."\n"";
}
else
{
print getStatisticName."value for bigram is ".$ll_value."\n"";
}
The Ngram Statistics Package (NSP) is a collection of perl modules that aid in
analyzing Ngrams in text files. We define an Ngram as a sequence of 'n' tokens
that occur within a window of at least 'n' tokens in the text; what
constitutes a "token" can be defined by the user.
NSP.pm is a stub that doesn't have any real functionality. It serves as a top
level module in the hierarchy and allows us to group the Text::NSP::Count and
Text::NSP::Measures modules.
The modules under Text::NSP::Measures implement measures of association that are
used to evaluate whether the co-occurrence of the words in a Ngram is purely
by chance or statistically significant. These measures compute a numerical
score for Ngrams. This score can be used to decide whether or not there is
enough evidence to reject the null hypothesis (that the Ngram is not
statistically significant) for that Ngram.
To use one of the measures you can either use the program statistic.pl provided
under the utils directory, or write your own driver program. Program
statistic.pl takes as input a list of Ngrams with their frequencies (in the
format output by count.pl) and runs a user-selected statistical measure of
association to compute the score for each Ngram. The Ngrams, along with their
scores, are output in descending order of this score. For help on using
utils/statistic.pl please refer to its perldoc (perldoc utils/statistic.pl).
If you are writing your own driver program, a basic usage example is provided
above under SYNOPSIS. For further clarification please refer to the
documentation of Text::NSP::Measures (perldoc Text::NSP::Measures).
The following table describes the error codes use in the implementation,
Error codes common to all the association measures.
100 - Trying to create an object of a abstract class.
200 - one of the required values is missing.
201 - one of the observed frequency comes out to be -ve.
202 - one of the frequency values(n11) exceeds the total no of
bigrams(npp) or a marginal total(n1p, np1).
203 - one of the marginal totals(n1p, np1) exceeds the total bigram
count(npp).
204 - one of the marginal totals is -ve.
Error Codes required by the mutual information measures
211 - one of the expected values is zero.
212 - one of the expected values is -ve.
Error codes required by the CHI measures.
221 - one of the expected values is zero.
Ted Pedersen, University of Minnesota Duluth
<tpederse at d.umn.edu>
Satanjeev Banerjee, Carnegie Mellon University
Amruta Purandare, University of Pittsburgh
Bridget Thomson-McInnes, University of Minnesota Twin Cities
Saiyam Kohli, University of Minnesota Duluth
Last updated: $Id: NSP.pm,v 1.44 2015/10/04 16:22:27 btmcinnes Exp $
<http://groups.yahoo.com/group/ngram/>
<http://ngram.sourceforge.net>
Copyright (C) 2000-2008, 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.
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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
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