manpagez: man pages & more
man Math::BigRat(3)
Home | html | info | man
Math::BigRat(3pm)      Perl Programmers Reference Guide      Math::BigRat(3pm)




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
       You can change the underlying module that does the low-level math
       operations by using:

               use Math::BigRat try => 'GMP';

       Note: This needs Math::BigInt::GMP installed.

       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 try => 'Foo,Math::BigInt::Bar';

       If you want to get warned when the fallback occurs, replace "try" with
       "lib":

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

       If you want the code to die instead, replace "try" with "only":

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


METHODS

       Any methods not listed here are derived 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.

   numify()
               my $y = $x->numify();

       Returns the object as a scalar. This will lose some data if the object
       cannot be represented by a normal Perl scalar (integer or float), so
       use as_int() or "as_float()" instead.

       This routine is automatically used whenever a scalar is required:

               my $x = Math::BigRat->new('3/1');
               @array = (0,1,2,3);
               $y = $array[$x];                # set $y to 3

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

               $x = Math::BigRat->new('2/3');
               print $x->as_float(5),"\n";             # '0.66667'

       Returns a copy of the object as BigFloat, preserving the accuracy as
       wanted, or the default of 40 digits.

       This method was added in v0.22 of Math::BigRat (April 2008).

   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.

   as_oct()
               $x = Math::BigRat->new('13');
               print $x->as_oct(),"\n";                # '015'

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

   from_hex()/from_bin()/from_oct()
               my $h = Math::BigRat->from_hex('0x10');
               my $b = Math::BigRat->from_bin('0b10000000');
               my $o = Math::BigRat->from_oct('020');

       Create a BigRat from an hexadecimal, binary or octal number in string
       form.

   length()
               $len = $x->length();

       Return the length of $x in digits for integer values.

   digit()
               print Math::BigRat->new('123/1')->digit(1);     # 1
               print Math::BigRat->new('123/1')->digit(-1);    # 3

       Return the N'ths digit from X when X is an integer value.

   bnorm()
               $x->bnorm();

       Reduce the number to the shortest form. This routine is called
       automatically whenever it is needed.

   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.

   bround()/round()/bfround()
       Are not yet implemented.

   bmod()
               $x->bmod($y);

       Returns $x modulo $y. When $x is finite, and $y is finite and non-zero,
       the result is identical to the remainder after floored division
       (F-division). If, in addition, both $x and $y are integers, the result
       is identical to the result from Perl's % operator.

   bneg()
               $x->bneg();

       Used to negate the object in-place.

   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()/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_positive()" is an alias for "is_pos()".

   is_neg()/is_negative()
               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();

       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.

   broot()
               $x->broot($n);

       Calculate the N'th root of $x.

   badd()
               $x->badd($y);

       Adds $y to $x and returns the result.

   bmul()
               $x->bmul($y);

       Multiplies $y to $x and returns the result.

   bsub()
               $x->bsub($y);

       Subtracts $y from $x and returns the result.

   bdiv()
               $q = $x->bdiv($y);
               ($q, $r) = $x->bdiv($y);

       In scalar context, divides $x by $y and returns the result. In list
       context, does floored division (F-division), returning an integer $q
       and a remainder $r so that $x = $q * $y + $r. The remainer (modulo) is
       equal to what is returned by "$x-"bmod($y)>.

   bdec()
               $x->bdec();

       Decrements $x by 1 and returns the result.

   binc()
               $x->binc();

       Increments $x by 1 and returns the result.

   copy()
               my $z = $x->copy();

       Makes a deep copy of the object.

       Please see the documentation in Math::BigInt for further details.

   bstr()/bsstr()
               my $x = Math::BigInt->new('8/4');
               print $x->bstr(),"\n";                  # prints 1/2
               print $x->bsstr(),"\n";                 # prints 1/2

       Return a string representing this object.

   bacmp()/bcmp()
       Used to compare numbers.

       Please see the documentation in Math::BigInt for further details.

   blsft()/brsft()
       Used to shift numbers left/right.

       Please see the documentation in Math::BigInt for further details.

   bpow()
               $x->bpow($y);

       Compute $x ** $y.

       Please see the documentation in Math::BigInt for further details.

   bexp()
               $x->bexp($accuracy);            # calculate e ** X

       Calculates two integers A and B so that A/B is equal to "e ** $x",
       where "e" is Euler's number.

       This method was added in v0.20 of Math::BigRat (May 2007).

       See also "blog()".

   bnok()
               $x->bnok($y);              # x over y (binomial coefficient n over k)

       Calculates the binomial coefficient n over k, also called the "choose"
       function. The result is equivalent to:

               ( n )      n!
               | - |  = -------
               ( k )    k!(n-k)!

       This method was added in v0.20 of Math::BigRat (May 2007).

   config()
               use Data::Dumper;

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

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

               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 accuracy 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 configuration values.
       This works only for values that a marked with a "RW" above, anything
       else is read-only.

   objectify()
       This is an internal routine that turns scalars into objects.


BUGS

       Please report any bugs or feature requests to "bug-math-bigrat at
       rt.cpan.org", or through the web interface at
       <https://rt.cpan.org/Ticket/Create.html?Queue=Math-BigRat> (requires
       login).  We will be notified, and then you'll automatically be notified
       of progress on your bug as I make changes.


SUPPORT

       You can find documentation for this module with the perldoc command.

           perldoc Math::BigRat

       You can also look for information at:

       o   RT: CPAN's request tracker

           <https://rt.cpan.org/Public/Dist/Display.html?Name=Math-BigRat>

       o   AnnoCPAN: Annotated CPAN documentation

           <http://annocpan.org/dist/Math-BigRat>

       o   CPAN Ratings

           <http://cpanratings.perl.org/dist/Math-BigRat>

       o   Search CPAN

           <http://search.cpan.org/dist/Math-BigRat/>

       o   CPAN Testers Matrix

           <http://matrix.cpantesters.org/?dist=Math-BigRat>

       o   The Bignum mailing list

           o   Post to mailing list

               "bignum at lists.scsys.co.uk"

           o   View mailing list

               <http://lists.scsys.co.uk/pipermail/bignum/>

           o   Subscribe/Unsubscribe

               <http://lists.scsys.co.uk/cgi-bin/mailman/listinfo/bignum>


LICENSE

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


SEE ALSO

       bigrat(3), Math::BigFloat(3) and Math::BigInt(3) as well as the
       backends Math::BigInt::FastCalc(3), Math::BigInt::GMP(3), and 
       Math::BigInt::Pari(3).


AUTHORS

       (C) by Tels <http://bloodgate.com/> 2001 - 2009.

       Currently maintained by Peter John Acklam <pjacklam@online.no>.



perl v5.24.0                      2016-03-01                 Math::BigRat(3pm)

perl 5.24 - Generated Wed Nov 16 19:42:06 CST 2016
© manpagez.com 2000-2017
Individual documents may contain additional copyright information.