1MT(3)                 User Contributed Perl Documentation                MT(3)
2
3
4

NAME

6       Math::Random::MT - The Mersenne Twister PRNG
7

SYNOPSIS

9         ## Object-oriented interface:
10         use Math::Random::MT;
11         $gen = Math::Random::MT->new()        # or...
12         $gen = Math::Random::MT->new($seed);  # or...
13         $gen = Math::Random::MT->new(@seeds);
14         $seed = $gen->get_seed();             # seed used to generate the random numbers
15         $rand = $gen->rand(42);               # random number in the interval [0, 42)
16         $dice = int($gen->rand(6)+1);         # random integer between 1 and 6
17         $coin = $gen->rand() < 0.5 ?          # flip a coin
18           "heads" : "tails"
19         $int = $gen->irand();                 # random integer in [0, 2^32-1]
20
21         ## Function-oriented interface:
22         use Math::Random::MT qw(srand rand irand);
23         # now use srand() and rand() as you usually do in Perl
24

DESCRIPTION

26       The Mersenne Twister is a pseudorandom number generator developed by
27       Makoto Matsumoto and Takuji Nishimura. It is described in their paper
28       at <URL:http://www.math.keio.ac.jp/~nisimura/random/doc/mt.ps>. This
29       algorithm has a very uniform distribution and is good for modelling
30       purposes but do not use it for cryptography.
31
32       This module implements two interfaces:
33
34   Object-oriented interface
35       new()
36           Creates a new generator that is automatically seeded based on
37           gettimeofday.
38
39       new($seed)
40           Creates a new generator seeded with an unsigned 32-bit integer.
41
42       new(@seeds)
43           Creates a new generator seeded with an array of (up to 624)
44           unsigned 32-bit integers.
45
46       set_seed()
47           Seeds the generator and returns the seed used. It takes the same
48           arguments as new().
49
50       get_seed()
51           Retrieves the value of the seed used.
52
53       rand($num)
54           Behaves exactly like Perl's builtin rand(), returning a number
55           uniformly distributed in [0, $num) ($num defaults to 1).
56
57       irand()
58           Returns a 32-bit integer, i.e. an integer uniformly distributed in
59           [0, 2^32-1].
60
61   Function-oriented interface
62       srand($seed)
63           Behaves just like Perl's builtin srand(). As in Perl >= 5.14, the
64           seed is returned. If you use this interface, it is strongly
65           recommended that you call srand() explicitly, rather than relying
66           on rand() to call it the first time it is used.
67
68       rand($num)
69           Behaves exactly like Perl's builtin rand(), returning a number
70           uniformly distributed in [0, $num) ($num defaults to 1).
71
72       irand()
73           Returns a 32-bit integer, i.e. an integer uniformly distributed in
74           [0, 2^32-1].
75

SEE ALSO

77       <URL:http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html>
78
79       Data::Entropy
80

ACKNOWLEDGEMENTS

82       Sean M. Burke
83           For giving me the idea to write this module.
84
85       Philip Newton
86           For several useful patches.
87
88       Florent Angly
89           For implementing seed generation and retrieval.
90

AUTHOR

92       Abhijit Menon-Sen <ams@toroid.org>
93
94       Copyright 2001 Abhijit Menon-Sen. All rights reserved.
95
96       Based on the C implementation of MT19937 Copyright (C) 1997 - 2002,
97       Makoto Matsumoto and Takuji Nishimura
98
99       This software is distributed under a (three-clause) BSD-style license.
100       See the LICENSE file in the distribution for details.
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104perl v5.34.0                      2022-01-21                             MT(3)
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