NAME

Set::Similarity::Dice - Dice coefficent 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
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 = $dice->similarity($bird,$mammal);

# from hashref sets
my $bird = {
  wings    => undef,
  eyes     => undef,
  feathers => undef,
  legs     => undef,
};
my $mammal = {
  eyes     => undef,
  hairs    => undef,
  legs     => undef,
  arms     => undef, 
};
my $similarity = $dice->from_sets($bird,$mammal); 

DESCRIPTION

Dice coefficient

The Dice coefficient is the number of elements in common to both sets relative to the average size of the total number of elements 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

Set::Similarity::Dice inherits all methods from Set::Similarity and implements the following new ones.

from_sets

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

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.