NAME

Math::Random::Discrete - Discrete random variables with general distributions

VERSION

version 1.02

SYNOPSIS

            

              
              
use Math::Random::Discrete;
my $fruit = Math::Random::Discrete->new(
    [ 40, 20, 10 ],
    [ 'Apple', 'Orange', 'Banana' ],
);
print $fruit->rand, "\n";
            
          

DESCRIPTION

Math::Random::Discrete generates discrete random variables according to a user-defined distribution. It uses Walker's alias method to create random values in O(1) time.

METHODS

new

            

              
              
my $generator = Math::Random::Discrete->new(\@weights, \@items);
            
          

Creates a random generator for the distribution given by values in @weights. These values can be probabilities, frequencies or any kind of weights. They don't have to add up to 1. @items is an array of items corresponding to the weights. If it is omitted, numbers 0, 1, 2, ... are used.

rand

            

              
              
my $item = $generator->rand;
            
          

Returns a random item according to the given distribution. That is, item i is returned with probability

            

              
              
p[i] = weight[i] / sum_of_all_weights
            
          

AUTHOR

Nick Wellnhofer <wellnhofer@aevum.de>

COPYRIGHT AND LICENSE

This software is copyright (c) 2015 by Nick Wellnhofer.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.