NAME
Set::Similarity::Cosine - Cosine similarity for sets
SYNOPSIS
use Set::Similarity::CosinePP;
# object method
my $cosine = Set::Similarity::CosinePP->new;
my $similarity = $cosine->similarity('Photographer','Fotograf');
# class method
my $cosine = 'Set::Similarity::CosinePP';
my $similarity = $cosine->similarity('Photographer','Fotograf');
# from 2-grams
my $width = 2;
my $similarity = $cosine->similarity('Photographer','Fotograf',$width);
# from arrayref of tokens
my $similarity = $cosine->similarity(['a','b'],['b']);
# from hashref of features
my $bird = {
wings => true,
eyes => true,
feathers => true,
hairs => false,
legs => true,
arms => false,
};
my $mammal = {
wings => false,
eyes => true,
feathers => false,
hairs => true,
legs => true,
arms => true,
};
my $similarity = $cosine->similarity($bird,$mammal);
# from arrayref sets
my $bird = [qw(
wings
eyes
feathers
legs
)];
my $mammal = [qw(
eyes
hairs
legs
arms
)];
my $similarity = $cosine->from_sets($bird,$mammal);
DESCRIPTION
Cosine similarity
A intersection B / (sqrt(A) * sqrt(B))
METHODS
Set::Similarity::CosinePP inherits all methods from Set::Similarity and
implements the following new ones.
from_sets
my $similarity = $object->from_sets(['a'],['b']);
This method expects two arrayrefs of strings as parameters. The
parameters are not checked, thus can lead to funny results or uncatched
divisions by zero.
If you want to use this method directly, you should take care that the
elements are unique. Also you should catch the situation where one of
the arrayrefs is empty (similarity is 0), or both are empty (similarity
is 1).
SOURCE REPOSITORY
AUTHOR
Helmut Wollmersdorfer,
COPYRIGHT AND LICENSE
Copyright (C) 2013-2014 by Helmut Wollmersdorfer
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.