stem.pl
Porter's stemming algorithm
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require 'stem.pl';
@stems = stem( @words );
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This routine applies the Porter Stemming Algorithm to its parameters,
returning the stemmed words.
It is derived from the C program ``stemmer.c''
as found in freewais and elsewhere, which contains these notes:
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Purpose: Implementation of the Porter stemming algorithm documented
in: Porter, M.F., "An Algorithm For Suffix Stripping,"
Program 14 (3), July 1980, pp. 130-137.
Provenance: Written by B. Frakes and C. Cox, 1986.
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I have re-interpreted areas that use Frakes and Cox's ``WordSize''
function. My version may misbehave on short words starting with ``y'',
but I can't think of any examples.
The step numbers correspond to Frakes and Cox, and are probably in
Porter's article (which I've not seen).
Porter's algorithm still has rough spots (e.g current/currency, -ings words),
which I've not attempted to cure, although I have added
support for the British -ise suffix.
This is version 0.1. I would welcome feedback, especially improvements
to the punctuation-stripping step.
Ian Phillipps <ian@unipalm.pipex.com>
Copyright Public IP Exchange Ltd (PIPEX).
Available for use under the same terms as perl.