Kevin Ryde >
Math-Factor-XS-0.40 >
Math::Factor::XS

Module Version: 0.40
Math::Factor::XS - Factorize numbers and calculate matching multiplications

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";

`Math::Factor::XS`

factorizes numbers by applying trial divisions.

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);

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);

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);

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does no longer have an effect as it has been superseded by `skip_multiples`

.

`factors()`

, `matches()`

and `prime_factors()`

are exportable.

`:all - *()`

Steven Schubiger <schubiger@cpan.org>

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

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