NAME

Set::Similarity - similarity measures for sets

SYNOPSIS

use Set::Similarity::Dice;

# object method
my $dice = Set::Similarity::Dice->new;
my $similarity = $dice->similarity('Photographer','Fotograf');

# class method
my $dice = 'Set::Similarity::Dice';
my $similarity = $dice->similarity('Photographer','Fotograf');

# from 2-grams
my $width = 2;
my $similarity = $dice->similarity('Photographer','Fotograf',$width);

# from arrayref of tokens
my $similarity = $dice->similarity(['a','b'],['b']);

# from hashref of features

# from hashref sets

DESCRIPTION

Overlap coefficient

( A intersect B ) / min(A,B)

Jaccard Index

The Jaccard coefficient measures similarity between sample sets, and is defined as the size of the intersection divided by the size of the union of the sample sets

( A intersect B ) / (A union B)

The Tanimoto coefficient is the ratio of the number of features common to both molecules to the total number of features, i.e.

( A intersect B ) / ( A + B - ( A intersect B ) ) # the same as Jaccard

The range is 0 to 1 inclusive.

Dice coefficient

The Dice coefficient is the number of features in common to both molecules relative to the average size of the total number of features present, i.e.

( A intersect B ) / 0.5 ( A + B ) # the same as sorensen

The weighting factor comes from the 0.5 in the denominator. The range is 0 to 1.

METHODS

new

$object = Set::Similarity->new();

similarity

my $similarity = $object->similarity('a','b');

from_tokens

my $similarity = $object->from_tokens(['a'],['b']);

from_sets

my $similarity = $object->from_sets({'a' => undef},{'b' => undef});

intersection

my $similarity = $object->from_tokens(['a'],['b']);

combined_length

my $similarity = $object->from_tokens(['a'],['b']);

min

my $similarity = $object->from_tokens(['a'],['b']);

ngrams

my $similarity = $object->from_tokens(['a'],['b']);

SOURCE REPOSITORY

http://github.com/wollmers/Set-Similarity

AUTHOR

Helmut Wollmersdorfer, <helmut.wollmersdorfer@gmail.com>

COPYRIGHT AND LICENSE

Copyright (C) 2013 by Helmut Wollmersdorfer

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

cpanm Set::Similarity

perl -MCPAN -e shell
install Set::Similarity