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Math::BigRat(3p) Perl Programmers Reference GuideMath::BigRat(3p)


NAME
       Math::BigRat - arbitrarily 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 arbitrarily 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 differ-
       ent 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 dif-
       ferent means of representing the numbers. See the respec-
       tive module documentation 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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Math::BigRat(3p) Perl Programmers Reference GuideMath::BigRat(3p)


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 vari-
       ous 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

       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.

       as_number()

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

       Returns a copy of the object as BigInt trunced it to inte-
       ger.







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Math::BigRat(3p) Perl Programmers Reference GuideMath::BigRat(3p)


       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);

       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_positive()

               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_negative()

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

       Return true if $x is negative (smaller than zero), other-
       wise false. Please note that '-inf' is also negative,



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Math::BigRat(3p) Perl Programmers Reference GuideMath::BigRat(3p)


       while 'NaN' and '+inf' aren't.

       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();

       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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Math::BigRat(3p) Perl Programmers Reference GuideMath::BigRat(3p)


               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
               upgrade         RW      To which class numbers are upgraded
                                       undef
               downgrade       RW      To which class numbers are downgraded
                                       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 configu-
       ration 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)

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

SEE ALSO
       Math::BigFloat and Math::Big as well as Math::Big-
       Int::BitVect, Math::BigInt::Pari and  Math::BigInt::GMP.

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

       The package at



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Math::BigRat(3p) Perl Programmers Reference GuideMath::BigRat(3p)


       <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, 2002, 2003,
       2004.


















































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