NAME

Math::Factor::XS - Factorize numbers and calculate matching multiplications

SYNOPSIS

use Math::Factor::XS ':all';
# or
use Math::Factor::XS qw(factors prime_factors matches);

$number = 30107;

@factors = factors($number);
@primes = prime_factors($number);
@matches = matches($number, \@factors);

print "$factors[1]\n";
print "$number == $matches[0][0] * $matches[0][1]\n";

DESCRIPTION

Math::Factor::XS factorizes numbers by applying trial divisions.

FUNCTIONS

factors

Find all factors (ie. divisors) of a number.

@factors = factors($number);

The number is factorized and its factors are returned as a list. For example,

@factors = factors(30);
#  @factors = (2, 3, 5, 6, 10, 15);

prime_factors

Find prime factors of a number.

@factors = prime_factors($number);

The number is factorized and its prime factors are returned as a list. Multiplying the list together gives $number. For example,

@primes = prime_factors(90);
#  @primes = (2, 3, 3, 5);

count_prime_factors

Return the count of prime factors of a number. This is the number of values returned by prime_factors().

my $count = count_prime_factors($number);

matches

Calculates matching multiplications.

@matches = matches($number, \@factors, { skip_multiples => [0|1] });

The factors will be multiplied against each other and all combinations that equal the number itself will be returned as a two-dimensional list. The matches are accessible through the indexes; for example, the first two numbers that matched the number may be accessed by $matches[0][0] and $matches[0][1], the second pair by $matches[1][0] and $matches[1][1], and so on.

The hashref provided at the end is optional. If skip_multiples is set to a true value, then matching multiplications that contain multiplicated small factors will be discarded. Example:

11 * 2737 == 30107 # accepted
77 * 391  == 30107 # discarded

Direct use of $Math::Factor::XS::Skip_multiple does no longer have an effect as it has been superseded by skip_multiples.

EXPORT

Functions

factors(), matches() and prime_factors() are exportable.

Tags

:all - *()

AUTHOR

Steven Schubiger <schubiger@cpan.org>

LICENSE

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

See http://dev.perl.org/licenses/