NAME

    Set::Similarity::BV - similarity measures for sets using fast bit
    vectors (BV)

SYNOPSIS

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

DESCRIPTION

    This is the base class including mainly helper and convenience methods.

 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 sets 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 sets
    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

    All methods can be used as class or object methods.

 new

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

 similarity

      my $similarity = $object->similarity($hex1,$hex2);

    $hex is a string of hexadecimal characters.

    $width must be integer, or defaults to 1.

 from_integers

      my $similarity = $object->from_integers($int1,$int2);

    Croaks if called directly. This method should be implemented in a child
    module.

 intersection

      my $intersection_size = $object->intersection($int1,$int2);

 combined_length

      my $set_size_sum = $object->combined_length($int1,$int2);

 min

      my $min = $object->min($int1,$int2);

SEE ALSO

    Set::Similarity::BV::Cosine

    Set::Similarity::BV::Dice

    Set::Similarity::BV::Jaccard

    Set::Similarity::BV::Overlap

SOURCE REPOSITORY

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

AUTHOR

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

COPYRIGHT AND LICENSE

    Copyright (C) 2016 by Helmut Wollmersdorfer

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