CONTENTS

• NAME
• SYNOPSIS
• DESCRIPTION
• BUGS
• AUTHOR

#NAME

Math::BigFloat - Arbitrary length float math package

#SYNOPSIS

use Math::BigFloat;
$f = Math::BigFloat->new($string);

$f->fadd(NSTR) return NSTR            addition
$f->fsub(NSTR) return NSTR            subtraction
$f->fmul(NSTR) return NSTR            multiplication
$f->fdiv(NSTR[,SCALE]) returns NSTR   division to SCALE places
$f->fmod(NSTR) returns NSTR           modular remainder
$f->fneg() return NSTR                negation
$f->fabs() return NSTR                absolute value
$f->fcmp(NSTR) return CODE            compare undef,<0,=0,>0
$f->fround(SCALE) return NSTR         round to SCALE digits
$f->ffround(SCALE) return NSTR        round at SCALEth place
$f->fnorm() return (NSTR)             normalize
$f->fsqrt([SCALE]) return NSTR        sqrt to SCALE places

#DESCRIPTION

All basic math operations are overloaded if you declare your big floats as

$float = new Math::BigFloat "2.123123123123123123123123123123123";

#number format

canonical strings have the form /[+-]\d+E[+-]\d+/ . Input values can have embedded whitespace.

#Error returns 'NaN'

An input parameter was "Not a Number" or divide by zero or sqrt of negative number.

#Division is computed to

max($Math::BigFloat::div_scale,length(dividend)+length(divisor)) digits by default. Also used for default sqrt scale.

#Rounding is performed

according to the value of $Math::BigFloat::rnd_mode:

trunc     truncate the value
zero      round towards 0
+inf      round towards +infinity (round up)
-inf      round towards -infinity (round down)
even      round to the nearest, .5 to the even digit
odd       round to the nearest, .5 to the odd digit

The default is even rounding.

#BUGS

The current version of this module is a preliminary version of the real thing that is currently (as of perl5.002) under development.

The printf subroutine does not use the value of $Math::BigFloat::rnd_mode when rounding values for printing. Consequently, the way to print rounded values is to specify the number of digits both as an argument to ffround and in the %f printf string, as follows:

printf "%.3f\n", $bigfloat->ffround(-3);

#AUTHOR

Mark Biggar Patches by John Peacock Apr 2001

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