Jarkko Hietaniemi >
perl-5.8.0 >
Math::BigRat

Module Version: 0.07
Math::BigRat - arbitrarily big rationals

use Math::BigRat; $x = Math::BigRat->new('3/7'); print $x->bstr(),"\n";

This is just a placeholder until the real thing is up and running. Watch this space...

Math with the numbers is done (by default) by a module called Math::BigInt::Calc. This is equivalent to saying:

use Math::BigRat lib => 'Calc';

You can change this by using:

use Math::BigRat lib => 'BitVect';

The following would first try to find Math::BigInt::Foo, then Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:

use Math::BigRat lib => 'Foo,Math::BigInt::Bar';

Calc.pm uses as internal format an array of elements of some decimal base (usually 1e7, but this might be differen for some systems) with the least significant digit first, while BitVect.pm uses a bit vector of base 2, most significant bit first. Other modules might use even different means of representing the numbers. See the respective module documentation for further details.

Any method not listed here is dervied from Math::BigFloat (or Math::BigInt), so make sure you check these two modules for further information.

$x = Math::BigRat->new('1/3');

Create a new Math::BigRat object. Input can come in various forms:

$x = Math::BigRat->new('1/3'); # simple string $x = Math::BigRat->new('1 / 3'); # spaced $x = Math::BigRat->new('1 / 0.1'); # w/ floats $x = Math::BigRat->new(Math::BigInt->new(3)); # BigInt $x = Math::BigRat->new(Math::BigFloat->new('3.1')); # BigFloat $x = Math::BigRat->new(Math::BigInt::Lite->new('2')); # BigLite

$n = $x->numerator();

Returns a copy of the numerator (the part above the line) as signed BigInt.

$d = $x->denominator();

Returns a copy of the denominator (the part under the line) as positive BigInt.

($n,$d) = $x->parts();

Return a list consisting of (signed) numerator and (unsigned) denominator as BigInts.

Returns a copy of the object as BigInt by truncating it to integer.

$x->bfac();

Calculates the factorial of $x. For instance:

print Math::BigRat->new('3/1')->bfac(),"\n"; # 1*2*3 print Math::BigRat->new('5/1')->bfac(),"\n"; # 1*2*3*4*5

Only works for integers for now.

Is not yet implemented.

Are not yet implemented.

Some things are not yet implemented, or only implemented half-way.

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

Math::BigFloat and Math::Big as well as Math::BigInt::BitVect, Math::BigInt::Pari and Math::BigInt::GMP.

The package at http://search.cpan.org/search?mode=module&query=Math%3A%3ABigRat may contain more documentation and examples as well as testcases.

(C) by Tels http://bloodgate.com/ 2001-2002.

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