# MirOS Manual: Math::BigRat(3p)

```
Math::BigRat(3p)Perl Programmers Reference Guide Math::BigRat(3p)
```

## NAME

```     Math::BigRat - Arbitrary big rational numbers
```

## SYNOPSIS

```             use Math::BigRat;

my \$x = Math::BigRat->new('3/7'); \$x += '5/9';

print \$x->bstr(),"\n";
print \$x ** 2,"\n";

my \$y = Math::BigRat->new('inf');
print "\$y ", (\$y->is_inf ? 'is' : 'is not') , " infinity\n";

my \$z = Math::BigRat->new(144); \$z->bsqrt();
```

## DESCRIPTION

```     Math::BigRat complements Math::BigInt and Math::BigFloat by
providing support for arbitrary big rational numbers.

MATH LIBRARY

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 different 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 documen-
tation for further details.

Currently the following replacement libraries exist, search
for them at CPAN:

Math::BigInt::BitVect
Math::BigInt::GMP
Math::BigInt::Pari
Math::BigInt::FastCalc

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```

## METHODS

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

new()

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

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

\$x = Math::BigRat->new(123);                            # scalars
\$x = Math::BigRat->new('inf');                          # infinity
\$x = Math::BigRat->new('123.3');                        # float
\$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

# You can also give D and N as different objects:
\$x = Math::BigRat->new(
Math::BigInt->new(-123),
Math::BigInt->new(7),
);                      # => -123/7

numerator()

\$n = \$x->numerator();

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

denominator()

\$d = \$x->denominator();

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

parts()

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

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

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as_int()

\$x = Math::BigRat->new('13/7');
print \$x->as_int(),"\n";                # '1'

Returns a copy of the object as BigInt, truncated to an
integer.

"as_number()" is an alias for "as_int()".

as_hex()

\$x = Math::BigRat->new('13');
print \$x->as_hex(),"\n";                # '0xd'

Returns the BigRat as hexadecimal string. Works only for
integers.

as_bin()

\$x = Math::BigRat->new('13');
print \$x->as_bin(),"\n";                # '0x1101'

Returns the BigRat as binary string. Works only for
integers.

bfac()

\$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

Works currently only for integers.

blog()

Is not yet implemented.

bround()/round()/bfround()

Are not yet implemented.

bmod()

use Math::BigRat;
my \$x = Math::BigRat->new('7/4');
my \$y = Math::BigRat->new('4/3');
print \$x->bmod(\$y);

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Set \$x to the remainder of the division of \$x by \$y.

is_one()

print "\$x is 1\n" if \$x->is_one();

Return true if \$x is exactly one, otherwise false.

is_zero()

print "\$x is 0\n" if \$x->is_zero();

Return true if \$x is exactly zero, otherwise false.

is_pos()

print "\$x is >= 0\n" if \$x->is_positive();

Return true if \$x is positive (greater than or equal to
zero), otherwise false. Please note that '+inf' is also
positive, while 'NaN' and '-inf' aren't.

"is_positive()" is an alias for "is_pos()".

is_neg()

print "\$x is < 0\n" if \$x->is_negative();

Return true if \$x is negative (smaller than zero), otherwise
false. Please note that '-inf' is also negative, while 'NaN'
and '+inf' aren't.

"is_negative()" is an alias for "is_neg()".

is_int()

print "\$x is an integer\n" if \$x->is_int();

Return true if \$x has a denominator of 1 (e.g. no fraction
parts), otherwise false. Please note that '-inf', 'inf' and
'NaN' aren't integer.

is_odd()

print "\$x is odd\n" if \$x->is_odd();

Return true if \$x is odd, otherwise false.

is_even()

print "\$x is even\n" if \$x->is_even();

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Return true if \$x is even, otherwise false.

bceil()

\$x->bceil();

Set \$x to the next bigger integer value (e.g. truncate the
number to integer and then increment it by one).

bfloor()

\$x->bfloor();

Truncate \$x to an integer value.

bsqrt()

\$x->bsqrt();

Calculate the square root of \$x.

config

use Data::Dumper;

print Dumper ( Math::BigRat->config() );
print Math::BigRat->config()->{lib},"\n";

Returns a hash containing the configuration, e.g. the ver-
sion number, lib loaded etc. The following hash keys are
currently filled in with the appropriate information.

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key             RO/RW   Description
Example
============================================================
lib             RO      Name of the Math library
Math::BigInt::Calc
lib_version     RO      Version of 'lib'
0.30
class           RO      The class of config you just called
Math::BigRat
version         RO      version number of the class you used
0.10
undef
undef
precision       RW      Global precision
undef
accuracy        RW      Global accuracy
undef
round_mode      RW      Global round mode
even
div_scale       RW      Fallback acccuracy for div
40
trap_nan        RW      Trap creation of NaN (undef = no)
undef
trap_inf        RW      Trap creation of +inf/-inf (undef = no)
undef

By passing a reference to a hash you may set the configura-
tion values. This works only for values that a marked with a
"RW" above, anything else is read-only.
```

## BUGS

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

inf handling (partial)
NaN handling (partial)
rounding (not implemented except for bceil/bfloor)
\$x ** \$y where \$y is not an integer
bmod(), blog(), bmodinv() and bmodpow() (partial)
```

```     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.

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See <http://search.cpan.org/search?dist=bignum> for a way to
use Math::BigRat.

The package at
<http://search.cpan.org/search?dist=Math%3A%3ABigRat> may
contain more documentation and examples as well as test-
cases.
```

## AUTHORS

```     (C) by Tels <http://bloodgate.com/> 2001 - 2005.

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```

Generated on 2016-04-09 18:24:16 by \$MirOS: src/scripts/roff2htm,v 1.83 2016/03/26 23:38:28 tg Exp \$

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