NAME
Math::Random::MT  The Mersenne Twister PRNG
SYNOPSIS
## Objectoriented interface:
use Math::Random::MT;
$gen = Math::Random::MT>new() # or...
$gen = Math::Random::MT>new($seed); # or...
$gen = Math::Random::MT>new(@seeds);
$seed = $gen>get_seed(); # seed used to generate the random numbers
$rand = $gen>rand(42); # random number in the interval [0, 42)
$dice = int($gen>rand(6)+1); # random integer between 1 and 6
$coin = $gen>rand() < 0.5 ? # flip a coin
"heads" : "tails"
$int = $gen>irand(); # random integer in [0, 2^321]
## Functionoriented interface:
use Math::Random::MT qw(srand rand irand);
# now use srand() and rand() as you usually do in Perl
DESCRIPTION
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 algorithm has a very uniform distribution and is good for modelling purposes but do not use it for cryptography.
This module implements two interfaces:
Objectoriented interface
 new()

Creates a new generator that is automatically seeded based on gettimeofday.
 new($seed)

Creates a new generator seeded with an unsigned 32bit integer.
 new(@seeds)

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

Seeds the generator and returns the seed used. It takes the same arguments as new().
 get_seed()

Retrieves the value of the seed used.
 rand($num)

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

Returns a 32bit integer, i.e. an integer uniformly distributed in [0, 2^321].
Functionoriented interface
 srand($seed)

Behaves just like Perl's builtin srand(). As in Perl >= 5.14, the seed is returned. 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.
 rand($num)

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

Returns a 32bit integer, i.e. an integer uniformly distributed in [0, 2^321].
SEE ALSO
<URL:http://www.math.sci.hiroshimau.ac.jp/~mmat/MT/emt.html>
Data::Entropy
ACKNOWLEDGEMENTS
 Sean M. Burke

For giving me the idea to write this module.
 Philip Newton

For several useful patches.
 Florent Angly

For implementing seed generation and retrieval.
AUTHOR
Abhijit MenonSen <ams@toroid.org>
Copyright 2001 Abhijit MenonSen. 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 (threeclause) BSDstyle license. See the LICENSE file in the distribution for details.