=head1 NAME
HTML::WordTagRatio::Ratio - Default module for determining the ratio of words to tags in a range of tokens in an HTML document.
=head1 SYNOPSIS
use HTML::WordTagRatio::Ratio;
use HTML::Content::HTMLTokenizer;
use HTML::Content::ContentExtractor;
my $tokenizer = new HTML::Content::HTMLTokenizer('TAG','WORD');
open(HTML,"index.html");
my $doc = join("",);
close(HTML);
my ($word_count_arr_ref,$tag_count_arr_ref,$token_type_arr_ref,$token_hash_ref) = $tokenizer->Tokenize($doc);
my $ratio = new HTML::WordTagRatio::Ratio();
my $value = $ratio->RangeValue(0, @$word_count_arr_ref,
$word_count_arr_ref, $tag_count_arr_ref);
=head1 DESCRIPTION
HTML::WordTagRatio::Ratio and derived classes compute a ratio of Words to Tags for a given range. Ratio is the base class and merely returns the number of word tokens in the range.
=head2 Methods
=over 4
=item * my $ratio = new HTML::WordTagRatio::Ratio()
Initializes HTML::WordTagRatio::Ratio
=item * my $value = $ratio->RangeValue($start, $end, \@WordCount, \@TagCount)
Returns the number of word tokens in ($start,$end]. $WordCount[$i] is the number of word tokens before or at the ith token in the input HTML document. $TagCount[$i] is the number of tag tokens before or at the ith token in the input HTML document.
=back
=head1 AUTHOR
Jean Tavernier (jj.tavernier@gmail.com)
=head1 COPYRIGHT
Copyright 2005 Jean Tavernier. All rights reserved.
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
=head1 SEE ALSO
ContentExtractorDriver.pl (1), HTML::Content::ContentExtractor (3), HTML::Content::HTMLTokenizer (3), HTML::WordTagRatio::WeightedRatio (3), HTML::WordTagRatio::SmoothedRatio (3), HTML::WordTagRatio::RelativeRatio (3), HTML::WordTagRatio::ExponentialRatio (3), HTML::WordTagRatio::NormalizedRatio (3).
=cut
package HTML::WordTagRatio::Ratio;
use strict;
use warnings;
use Carp;
use fields qw(Exists);
# new - constructs Ratio object
# - preconditions: none
# - postconditions: Ratio is constructed
sub new
{
my $invocant = shift;
my $class = ref($invocant) || $invocant;
my $self = fields::new($invocant);
$self->{Exists} = 1;
return bless($self, $class);
}
# RangeValue - returns value of a range of tokens
# - preconditions: 1st arg is an integer >= 0 and < length of @{3rd argument}
# 2nd arg is an integer > 1st arg and < length of @{3rd argument}
# 3rd arg is an array ref which points to an array of monotonically
# increasing integers, indicating the number of words found
# in the HTML document before or at the i_th token (i being an
# index into the array)
# 4th arg is an array ref which points to an array of monotonically
# increasing integers, indicating the number of tags found
# in the HTML document before or at the i_th token (i being an
# index into the array)
# - postconditions: floating point value returned indicating the value of the range
sub RangeValue
{
my $self = shift;
my $i = shift;
my $j = shift;
my $tN = shift;
my $tT = shift;
my @N = @{$tN};
my @T = @{$tT};
if ($j <= $i)
{
return -1;
}
my $NinRange = $N[$j] - $N[$i];
my $TinRange = $T[$j] - $T[$i];
return $NinRange;
}
1;