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.\" ========================================================================
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.IX Title "AI::Categorizer::FeatureVector 3"
.TH AI::Categorizer::FeatureVector 3 "2008-01-14" "perl v5.8.8" "User Contributed Perl Documentation"
.SH "NAME"
AI::Categorizer::FeatureVector \- Features vs. Values
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 4
\&  my $f1 = new AI::Categorizer::FeatureVector
\&    (features => {howdy => 2, doody => 3});
\&  my $f2 = new AI::Categorizer::FeatureVector
\&    (features => {doody => 1, whopper => 2});
.Ve
.PP
.Vb 6
\&  @names = $f1->names;
\&  $x = $f1->length;
\&  $x = $f1->sum;
\&  $x = $f1->includes('howdy');
\&  $x = $f1->value('howdy');
\&  $x = $f1->dot($f2);
.Ve
.PP
.Vb 3
\&  $f3 = $f1->clone;
\&  $f3 = $f1->intersection($f2);
\&  $f3 = $f1->add($f2);
.Ve
.PP
.Vb 2
\&  $h = $f1->as_hash;
\&  $h = $f1->as_boolean_hash;
.Ve
.PP
.Vb 1
\&  $f1->normalize;
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This class implements a \*(L"feature vector\*(R", which is a flat data
structure indicating the values associated with a set of features.  At
its base level, a FeatureVector usually represents the set of words in
a document, with the value for each feature indicating the number of
times each word appears in the document.  However, the values are
arbitrary so they can represent other quantities as well, and
FeatureVectors may also be combined to represent the features of
multiple documents.
.SH "METHODS"
.IX Header "METHODS"
.IP "..." 4
.SH "AUTHOR"
.IX Header "AUTHOR"
Ken Williams, ken@mathforum.org
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 2000\-2003 Ken Williams.  All rights reserved.
.PP
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fIAI::Categorizer\fR\|(3), \fIStorable\fR\|(3)