NAME

Math::Random::MT::Auto::Range - Range-valued PRNGs

SYNOPSIS

use strict;
use warnings;
use Math::Random::MT::Auto::Range;

# Integer random number range
my $die = Math::Random::MT::Auto::Range->new(LO => 1, HI => 6);
my $roll = $die->rrand();

# Floating-point random number range
my $compass = Math::Random::MT::Auto::Range->new(LO => 0, HI => 360,
                                                 TYPE => 'DOUBLE');
my $course = $compass->rrand();

DESCRIPTION

This module creates range-valued pseudorandom number generators (PRNGs) that return random values between two specified limits.

While useful in itself, the primary purpose of this module is to provide an example of how to create subclasses of Math::Random::MT::Auto within the inside-out object model.

MODULE DECLARATION

Add the following to the top of our application code:

use strict;
use warnings;
use Math::Random::MT::Auto::Range;

This module is strictly OO, and does not export any functions or symbols.

METHODS

Math::Random::MT::Auto::Range->new

Creates a new range-valued PRNG.

my $prng = Math::Random::MT::Auto::Range->new( %options );

Available options are:

'LOW' => $num

'HIGH' => $num

Sets the limits over which the values return by the PRNG will range. These arguments are mandatory, and LOW must not be equal to HIGH.

If the TYPE for the PRNG is INTEGER, then the range will be LOW to HIGH inclusive (i.e., [LOW, HIGH]). If DOUBLE, then LOW inclusive to HIGH exclusive (i.e., [LOW, HIGH)).

LO and HI can be used as synonyms for LOW and HIGH, respectively.

'TYPE' => 'INTEGER'

'TYPE' => 'DOUBLE'

Sets the type for the values returned from the PRNG. If TYPE is not specified, it will default to INTEGER if both LOW and HIGH are integers.

The options above are also supported using lowercase and mixed-case (e.g., 'low', 'hi', 'Type', etc.).

Additionally, objects created with this package can take any of the options supported by the Math::Random::MT::Auto class, namely, STATE, SEED and STATE.

$obj->new

Creates a new PRNG in the same manner as "Math::Random::MT::Auto::Range->new".

my $prng2 = $prng1->new( %options );

$obj->clone

Creates a new PRNG that is a copy of the referenced PRNG.

my $prng2 = $prng1->clone();

In addition to the methods describe below, the objects created by this package also support all the object methods provided by the Math::Random::MT::Auto class.

$obj->rrand

Returns a random number of the configured type within the configured range.

my $rand = $prng->rrand();

If the TYPE for the PRNG is INTEGER, then the range will be LOW to HIGH inclusive (i.e., [LOW, HIGH]). If DOUBLE, then LOW inclusive to HIGH exclusive (i.e., [LOW, HIGH)).

$obj->set_range_type

Sets the numeric type for the random numbers returned by the PRNG.

$prng->set_range_type('INTEGER');
  # or
$prng->set_range_type('DOUBLE');

$obj->get_range_type

Returns the numeric type ('INTEGER' or 'DOUBLE') for the random numbers returned by the PRNG.

my $type = $prng->get_range_type();

$obj->set_range

Sets the limits for the PRNG's return value range.

$prng->set_range($lo, $hi);

$lo must not be equal to $hi.

$obj->get_range

Returns a list of the PRNG's range limits.

my ($lo, $hi) = $prng->get_range();

DIAGNOSTICS

• Missing parameter: LOW

• Missing parameter: HIGH

  The LOW and HIGH values for the range must be specified to ->new().

• Arg to ->set_range_type() must be 'INTEGER' or 'DOUBLE'

  Self explanatory.

• ->range() requires two numeric args

  Self explanatory.

• Invalid arguments: LOW and HIGH are equal

  You cannot specify a range of zero width.

This module will reverse the range limits if they are specified in the wrong order (i.e., it makes sure that LOW < HIGH).

SEE ALSO

Math::Random::MT::Auto

AUTHOR

Jerry D. Hedden, <jdhedden AT 1979 DOT usna DOT com>

COPYRIGHT AND LICENSE

Copyright 2005 Jerry D. Hedden. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.