Math::Random::MT - The Mersenne Twister PRNG

Math-Random-MT documentation Contained in the Math-Random-MT distribution.

Index

Code Index:

NAME

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Math::Random::MT - The Mersenne Twister PRNG

SYNOPSIS

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 use Math::Random::MT;

 $gen = Math::Random::MT->new($seed); # OR...
 $gen = Math::Random::MT->new(@seed);

 print $gen->rand(3);

 OR

 use Math::Random::MT qw(srand rand);

 # now srand and rand behave as usual.

DESCRIPTION

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The Mersenne Twister is a pseudorandom number generator developed by Makoto Matsumoto and Takuji Nishimura. It is described in their paper at <URL:http://www.math.keio.ac.jp/~nisimura/random/doc/mt.ps>.

This module implements two interfaces, as described in the synopsis above. It defines the following functions.

Functions

new($seed)

Creates a new generator seeded with an unsigned 32-bit integer.

new(@seed)

Creates a new generator seeded with an array of (up to 624) unsigned 32-bit integers.

rand($num)

Behaves exactly like Perl's builtin rand(), returning a number uniformly distributed in [0, $num) ($num defaults to 1).

srand($seed)

This is an alternative interface to the module's functionality. It behaves just like Perl's builtin srand(). If you use this interface, it is strongly recommended that you call srand() explicitly, rather than relying on rand() to call it the first time it is used.

SEE ALSO

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<URL:http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html>

Math::TrulyRandom

ACKNOWLEDGEMENTS

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Sean M. Burke

For giving me the idea to write this module.

Philip Newton

For several useful patches.

AUTHOR

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Abhijit Menon-Sen <ams@toroid.org>

Copyright 2001 Abhijit Menon-Sen. All rights reserved.

Based on the C implementation of MT19937 Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura

This software is distributed under a (three-clause) BSD-style license. See the LICENSE file in the distribution for details.

Math-Random-MT documentation Contained in the Math-Random-MT distribution. 
package Math::Random::MT;

use strict;
use Carp;
use DynaLoader;
use vars qw( @ISA $VERSION );

my $gen = undef;
@ISA = qw( DynaLoader );
$VERSION = '1.12';

bootstrap Math::Random::MT $VERSION;

sub new
{
    my $class = shift;

    if ( @_ == 1 ) {
        return Math::Random::MT::setup( shift );
    }
    else {
        return Math::Random::MT::setup_array( @_ );
    }
}

sub rand
{
    my ($self, $N) = @_;
    if (ref $self) {
        return ($N || 1) * $self->genrand();
    }
    else {
        $N = $self;
        Math::Random::MT::srand() unless defined $gen;
        return ($N || 1) * $gen->genrand();
    }
}

# Don't rely on the default seed.
sub srand { $gen = new Math::Random::MT (shift || time); }

sub import
{
    no strict 'refs';
    my $pkg = caller;

    foreach my $sym (@_) {
        if ($sym eq "srand" || $sym eq "rand") {
            *{"${pkg}::$sym"} = \&$sym;
        }
    }
}

1;

__END__