README
1NAME
2 Math::Random::OO - Consistent object-oriented interface for generating
3 random numbers
4
5VERSION
6 version 0.22
7
8SYNOPSIS
9 # Using factory functions
10 use Math::Random::OO qw( Uniform UniformInt );
11 push @prngs, Uniform(), UniformInt(1,6);
12
13 # Explicit creation of subclasses
14 use Math::Random::OO::Normal;
15 push @prngs, Math::Random::OO::Normal->new(0,2);
16
17 $_->seed(23) for (@prngs);
18 print( $_->next(), "\n") for (@prngs);
19
20DESCRIPTION
21 CPAN contains many modules for generating random numbers in various ways
22 and from various probability distributions using pseudo-random number
23 generation algorithms or other entropy sources. (The "SEE ALSO" section
24 has some examples.) Unfortunately, no standard interface exists across
25 these modules. This module defines an abstract interface for random
26 number generation. Subclasses of this model will implement specific
27 types of random number generators or will wrap existing random number
28 generators.
29
30 This consistency will come at the cost of some efficiency, but will
31 enable generic routines to be written that can manipulate any provided
32 random number generator that adheres to the interface. E.g., a
33 stochastic simulation could take a number of user-supplied parameters,
34 each of which is a Math::Random::OO subclass object and which represent
35 a stochastic variable with a particular probability distribution.
36
37USAGE
38 Factory Functions
39 use Math::Random::OO qw( Uniform UniformInt Normal Bootstrap );
40 $uniform = Uniform(-1,1);
41 $uni_int = UniformInt(1,6);
42 $normal = Normal(1,1);
43 $boot = Bootstrap( 2, 3, 3, 4, 4, 4, 5, 5, 5 );
44
45 In addition to defining the abstract interface for subclasses, this
46 module imports subclasses and exports factory functions upon request to
47 simplify creating many random number generators at once without typing
48 "Math::Random::OO::Subclass->new()" each time. The factory function
49 names are the same as the suffix of the subclass following
50 "Math::Random::OO". When called, they pass their arguments directly to
51 the "new" constructor method of the corresponding subclass and return a
52 new object of the subclass type. Supported functions and their
53 subclasses include:
54
55 * "Uniform" -- Math::Random::OO::Uniform (uniform distribution over a
56 range)
57
58 * "UniformInt" -- Math::Random::OO::UniformInt (uniform distribution
59 of integers over a range)
60
61 * "Normal" -- Math::Random::OO::Normal (normal distribution with
62 specified mean and standard deviation)
63
64 * "Bootstrap" -- Math::Random::OO::Bootstrap (bootstrap resampling
65 from a non-parameteric distribution)
66
67INTERFACE
68 All Math::Random::OO subclasses must follow a standard interface. They
69 must provide a "new" method, a "seed" method, and a "next" method.
70 Specific details are left to each interface.
71
72 "new"
73 This is the standard constructor. Each subclass will define parameters
74 specific to the subclass.
75
76 "seed"
77 $prng->seed( @seeds );
78
79 This method takes seed (or list of seeds) and uses it to set the initial
80 state of the random number generator. As some subclasses may optionally
81 use/require a list of seeds, the interface mandates that a list must be
82 acceptable. Generators requiring a single seed must use the first value
83 in the list.
84
85 As seeds may be passed to the built-in "srand()" function, they may be
86 truncated as integers, so 0.12 and 0.34 would be the same seed. Only
87 positive integers should be used.
88
89 "next"
90 $rnd = $prng->next();
91
92 This method returns the next random number from the random number
93 generator. It does not take (and must not use) any parameters.
94
95SEE ALSO
96 This is not an exhaustive list -- search CPAN for that -- but represents
97 some of the more common or established random number generators that
98 I've come across.
99
100 Math::Random -- multiple random number generators for different
101 distributions (a port of the C randlib)
102 Math::Rand48 -- perl bindings for the drand48 library (according to
103 perl56delta, this may already be the default after perl 5.005_52 if
104 available)
105 Math::Random::MT -- The Mersenne Twister PRNG (good and fast)
106 Math::TrulyRandom -- an interface to random numbers from interrupt
107 timing discrepancies
108
109SUPPORT
110 Bugs / Feature Requests
111 Please report any bugs or feature requests through the issue tracker at
112 <https://github.com/dagolden/math-random-oo/issues>. You will be
113 notified automatically of any progress on your issue.
114
115 Source Code
116 This is open source software. The code repository is available for
117 public review and contribution under the terms of the license.
118
119 <https://github.com/dagolden/math-random-oo>
120
121 git clone git://github.com/dagolden/math-random-oo.git
122
123AUTHOR
124 David Golden <dagolden@cpan.org>
125
126COPYRIGHT AND LICENSE
127 This software is Copyright (c) 2013 by David Golden.
128
129 This is free software, licensed under:
130
131 The Apache License, Version 2.0, January 2004
132
133