Florent Angly > Math-Random-MT-1.14_1 > Math::Random::MT

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Module Version: 1.14_1   Source   Latest Release: Math-Random-MT-1.16

# NAME

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

# SYNOPSIS

```  ## Object-oriented 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

## Function-oriented interface:
use Math::Random::MT qw(srand rand);
# 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:

## Object-oriented interface

new()

Creates a new generator that is automatically seeded based on gettimeofday.

new(\$seed)

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

new(@seeds)

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

set_seed()

Seeds the generator. 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).

## Function-oriented interface

rand(\$num)

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

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.

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 Menon-Sen <ams@toroid.org>