NAME

Algorithm::FeatureSelection -

SYNOPSIS

use Algorithm::FeatureSelection;
my $fs = Algorithm::FeatureSelection->new();

# feature-class data structure ...
my $features = {
  feature_1 => {
      class_a => 10,
      class_b => 2,
  },
  feature_2 => {
      class_b => 11,
      class_d => 32
  },
        .
        .
        .
};

# get pairwise-mutula-information
my $pmi = $fs->calc_pairwise_mutual_information($features);
my $pmi = $fs->calc_pmi($features); # same above

# get information-gain 
my $ig = $fs->calc_information_gain($features);
my $ig = $fs->calc_ig($features); # same above

DESCRIPTION

This library is an perl implementation of 'Pairwaise Mutual Information' and 'Information Gain' that are used as well-known method of feature selection on text mining fields.

METHOD

new()

calc_information_gain( $features )

my $features = {
  feature_1 => {
      class_a => 10,
      class_b => 2,
  },
  feature_2 => {
      class_b => 11,
      class_d => 32
  },
        .
        .
        .
};
my $fs = Algorithm::FeatureSelection->new();
my $ig = $fs->information_gain($features);

calc_ig( $features )

short name of calc_information_gain()

calc_pairwise_mutual_information( $features )

my $features = {
  feature_1 => {
      class_a => 10,
      class_b => 2,
  },
  feature_2 => {
      class_b => 11,
      class_d => 32
  },
        .
        .
        .
};
my $fs = Algorithm::FeatureSelection->new();
my $pmi = $fs->calc_pairwise_mutual_information($features);

calc_pmi( $features )

short name of calc_pairwise_mutual_information()

calc_entropy(HASH|ARRAY)

calcurate entropy. 

AUTHOR

Takeshi Miki <miki@cpan.org>

SEE ALSO

LICENSE

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