diff options
Diffstat (limited to 'lib/Math/BigFloat.pm')
| -rw-r--r-- | lib/Math/BigFloat.pm | 127 |
1 files changed, 78 insertions, 49 deletions
diff --git a/lib/Math/BigFloat.pm b/lib/Math/BigFloat.pm index 92e701666f..7551ad01a3 100644 --- a/lib/Math/BigFloat.pm +++ b/lib/Math/BigFloat.pm @@ -5,31 +5,31 @@ use Math::BigInt; use Exporter; # just for use to be happy @ISA = (Exporter); -%OVERLOAD = ( - # Anonymous subroutines: -'+' => sub {new BigFloat &fadd}, -'-' => sub {new BigFloat +use overload +'+' => sub {new Math::BigFloat &fadd}, +'-' => sub {new Math::BigFloat $_[2]? fsub($_[1],${$_[0]}) : fsub(${$_[0]},$_[1])}, -'<=>' => sub {new BigFloat +'<=>' => sub {new Math::BigFloat $_[2]? fcmp($_[1],${$_[0]}) : fcmp(${$_[0]},$_[1])}, -'cmp' => sub {new BigFloat +'cmp' => sub {new Math::BigFloat $_[2]? ($_[1] cmp ${$_[0]}) : (${$_[0]} cmp $_[1])}, -'*' => sub {new BigFloat &fmul}, -'/' => sub {new BigFloat +'*' => sub {new Math::BigFloat &fmul}, +'/' => sub {new Math::BigFloat $_[2]? scalar fdiv($_[1],${$_[0]}) : scalar fdiv(${$_[0]},$_[1])}, -'neg' => sub {new BigFloat &fneg}, -'abs' => sub {new BigFloat &fabs}, +'neg' => sub {new Math::BigFloat &fneg}, +'abs' => sub {new Math::BigFloat &fabs}, qw( "" stringify 0+ numify) # Order of arguments unsignificant -); +; sub new { - my $foo = fnorm($_[1]); - panic("Not a number initialized to BigFloat") if $foo eq "NaN"; - bless \$foo; + my ($class) = shift; + my ($foo) = fnorm(shift); + panic("Not a number initialized to Math::BigFloat") if $foo eq "NaN"; + bless \$foo, $class; } sub numify { 0 + "${$_[0]}" } # Not needed, additional overhead # comparing to direct compilation based on @@ -58,21 +58,6 @@ sub stringify { return $n; } -# Arbitrary length float math package -# -# by Mark Biggar -# -# number format -# canonical strings have the form /[+-]\d+E[+-]\d+/ -# Input values can have inbedded whitespace -# Error returns -# 'NaN' An input parameter was "Not a Number" or -# divide by zero or sqrt of negative number -# Division is computed to -# max($div_scale,length(dividend)+length(divisor)) -# digits by default. -# Also used for default sqrt scale - $div_scale = 40; # Rounding modes one of 'even', 'odd', '+inf', '-inf', 'zero' or 'trunc'. @@ -84,21 +69,6 @@ sub fneg; sub fabs; sub fcmp; sub fround; sub ffround; sub fnorm; sub fsqrt; -# bigfloat routines -# -# fadd(NSTR, NSTR) return NSTR addition -# fsub(NSTR, NSTR) return NSTR subtraction -# fmul(NSTR, NSTR) return NSTR multiplication -# fdiv(NSTR, NSTR[,SCALE]) returns NSTR division to SCALE places -# fneg(NSTR) return NSTR negation -# fabs(NSTR) return NSTR absolute value -# fcmp(NSTR,NSTR) return CODE compare undef,<0,=0,>0 -# fround(NSTR, SCALE) return NSTR round to SCALE digits -# ffround(NSTR, SCALE) return NSTR round at SCALEth place -# fnorm(NSTR) return (NSTR) normalize -# fsqrt(NSTR[, SCALE]) return NSTR sqrt to SCALE places - - # Convert a number to canonical string form. # Takes something that looks like a number and converts it to # the form /^[+-]\d+E[+-]\d+$/. @@ -154,7 +124,7 @@ sub fmul { #(fnum_str, fnum_str) return fnum_str &norm(Math::BigInt::bmul($xm,$ym),$xe+$ye); } } - + # addition sub fadd { #(fnum_str, fnum_str) return fnum_str local($x,$y) = (fnorm($_[$[]),fnorm($_[$[+1])); @@ -192,7 +162,7 @@ sub fdiv #(fnum_str, fnum_str[,scale]) return fnum_str $xe-$ye-$scale); } } - + # round int $q based on fraction $r/$base using $rnd_mode sub round { #(int_str, int_str, int_str) return int_str local($q,$r,$base) = @_; @@ -233,7 +203,7 @@ sub fround { #(fnum_str, scale) return fnum_str } } } - + # round $x at the 10 to the $scale digit place sub ffround { #(fnum_str, scale) return fnum_str local($x,$scale) = (fnorm($_[$[]),$_[$[+1]); @@ -273,7 +243,7 @@ sub fcmp #(fnum_str, fnum_str) return cond_code ); } } - + # square root by Newtons method. sub fsqrt { #(fnum_str[, scale]) return fnum_str local($x, $scale) = (fnorm($_[$[]), $_[$[+1]); @@ -290,8 +260,67 @@ sub fsqrt { #(fnum_str[, scale]) return fnum_str $guess = fmul(fadd($guess,fdiv($x,$guess,$gs*2)),".5"); $gs *= 2; } - new BigFloat &fround($guess, $scale); + new Math::BigFloat &fround($guess, $scale); } } 1; +__END__ + +=head1 NAME + +Math::BigFloat - Arbitrary length float math package + +=head1 SYNOPSIS + + use Math::BogFloat; + $f = Math::BigFloat->new($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->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 + +=head1 DESCRIPTION + +All basic math operations are overloaded if you declare your big +floats as + + $float = new Math::BigFloat "2.123123123123123123123123123123123"; + +=over 2 + +=item number format + +canonical strings have the form /[+-]\d+E[+-]\d+/ . Input values can +have inbedded whitespace. + +=item Error returns 'NaN' + +An input parameter was "Not a Number" or divide by zero or sqrt of +negative number. + +=item Division is computed to + +C<max($div_scale,length(dividend)+length(divisor))> digits by default. +Also used for default sqrt scale. + +=back + +=head1 BUGS + +The current version of this module is a preliminary version of the +real thing that is currently (as of perl5.002) under development. + +=head1 AUTHOR + +Mark Biggar + +=cut |