diff options
Diffstat (limited to 'contrib/perl5/lib/Math/BigFloat.pm')
| -rw-r--r-- | contrib/perl5/lib/Math/BigFloat.pm | 84 |
1 files changed, 63 insertions, 21 deletions
diff --git a/contrib/perl5/lib/Math/BigFloat.pm b/contrib/perl5/lib/Math/BigFloat.pm index d8d643c..1eefac2 100644 --- a/contrib/perl5/lib/Math/BigFloat.pm +++ b/contrib/perl5/lib/Math/BigFloat.pm @@ -4,6 +4,7 @@ use Math::BigInt; use Exporter; # just for use to be happy @ISA = (Exporter); +$VERSION = '0.02'; use overload '+' => sub {new Math::BigFloat &fadd}, @@ -12,9 +13,12 @@ use overload '<=>' => sub {$_[2]? fcmp($_[1],${$_[0]}) : fcmp(${$_[0]},$_[1])}, 'cmp' => sub {$_[2]? ($_[1] cmp ${$_[0]}) : (${$_[0]} cmp $_[1])}, '*' => sub {new Math::BigFloat &fmul}, -'/' => sub {new Math::BigFloat +'/' => sub {new Math::BigFloat $_[2]? scalar fdiv($_[1],${$_[0]}) : scalar fdiv(${$_[0]},$_[1])}, +'%' => sub {new Math::BigFloat + $_[2]? scalar fmod($_[1],${$_[0]}) : + scalar fmod(${$_[0]},$_[1])}, 'neg' => sub {new Math::BigFloat &fneg}, 'abs' => sub {new Math::BigFloat &fabs}, @@ -43,12 +47,15 @@ sub stringify { my $e = $1; my $ln = length($n); - if ($e > 0) { - $n .= "0" x $e . '.'; - } elsif (abs($e) < $ln) { - substr($n, $ln + $e, 0) = '.'; - } else { - $n = '.' . ("0" x (abs($e) - $ln)) . $n; + if ( defined $e ) + { + if ($e > 0) { + $n .= "0" x $e . '.'; + } elsif (abs($e) < $ln) { + substr($n, $ln + $e, 0) = '.'; + } else { + $n = '.' . ("0" x (abs($e) - $ln)) . $n; + } } $n = "-$n" if $minus; @@ -85,6 +92,7 @@ sub fnorm { #(string) return fnum_str # normalize number -- for internal use sub norm { #(mantissa, exponent) return fnum_str local($_, $exp) = @_; + $exp = 0 unless defined $exp; if ($_ eq 'NaN') { 'NaN'; } else { @@ -140,7 +148,7 @@ sub fadd { #(fnum_str, fnum_str) return fnum_str # subtraction sub fsub { #(fnum_str, fnum_str) return fnum_str - fadd($_[$[],fneg($_[$[+1])); + fadd($_[$[],fneg($_[$[+1])); } # division @@ -164,6 +172,27 @@ sub fdiv #(fnum_str, fnum_str[,scale]) return fnum_str } } +# modular division +# args are dividend, divisor +sub fmod #(fnum_str, fnum_str) return fnum_str +{ + local($x,$y) = (fnorm($_[$[]),fnorm($_[$[+1])); + if ($x eq 'NaN' || $y eq 'NaN' || $y eq '+0E+0') { + 'NaN'; + } else { + local($xm,$xe) = split('E',$x); + local($ym,$ye) = split('E',$y); + if ( $xe < $ye ) + { + $ym .= ('0' x ($ye-$xe)); + } + else + { + $xm .= ('0' x ($xe-$ye)); + } + &norm(Math::BigInt::bmod($xm,$ym)); + } +} # 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) = @_; @@ -174,12 +203,14 @@ sub round { #(int_str, int_str, int_str) return int_str } else { local($cmp) = Math::BigInt::bcmp(Math::BigInt::bmul($r,'+2'),$base); if ( $cmp < 0 || - ($cmp == 0 && - ( $rnd_mode eq 'zero' || + ($cmp == 0 && ( + ($rnd_mode eq 'zero' ) || ($rnd_mode eq '-inf' && (substr($q,$[,1) eq '+')) || ($rnd_mode eq '+inf' && (substr($q,$[,1) eq '-')) || - ($rnd_mode eq 'even' && $q =~ /[24680]$/) || - ($rnd_mode eq 'odd' && $q =~ /[13579]$/) )) ) { + ($rnd_mode eq 'even' && $q =~ /[24680]$/ ) || + ($rnd_mode eq 'odd' && $q =~ /[13579]$/ ) ) + ) + ) { $q; # round down } else { Math::BigInt::badd($q, ((substr($q,$[,1) eq '-') ? '-1' : '+1')); @@ -199,7 +230,7 @@ sub fround { #(fnum_str, scale) return fnum_str $x; } else { &norm(&round(substr($xm,$[,$scale+1), - "+0".substr($xm,$[+$scale+1,1),"+10"), + "+0".substr($xm,$[+$scale+1),"+1"."0" x length(substr($xm,$[+$scale+1))), $xe+length($xm)-$scale-1); } } @@ -223,15 +254,17 @@ sub ffround { #(fnum_str, scale) return fnum_str # normalized "-0" to &round when rounding -0.006 (for # example), purely so &round won't lose the sign. &norm(&round(substr($xm,$[,1).'0', - "+0".substr($xm,$[+1,1),"+10"), $scale); + "+0".substr($xm,$[+1), + "+1"."0" x length(substr($xm,$[+1))), $scale); } else { &norm(&round(substr($xm,$[,$xe), - "+0".substr($xm,$[+$xe,1),"+10"), $scale); + "+0".substr($xm,$[+$xe), + "+1"."0" x length(substr($xm,$[+$xe))), $scale); } } } } - + # compare 2 values returns one of undef, <0, =0, >0 # returns undef if either or both input value are not numbers sub fcmp #(fnum_str, fnum_str) return cond_code @@ -244,9 +277,17 @@ sub fcmp #(fnum_str, fnum_str) return cond_code if ($xm eq '+0' || $ym eq '+0') { return $xm <=> $ym; } - ord($y) <=> ord($x) - || ($xe <=> $ye) * (substr($x,$[,1).'1') - || Math::BigInt::cmp($xm,$ym); + if ( $xe < $ye ) # adjust the exponents to be equal + { + $ym .= '0' x ($ye - $xe); + $ye = $xe; + } + elsif ( $ye < $xe ) # same here + { + $xm .= '0' x ($xe - $ye); + $xe = $ye; + } + return Math::BigInt::cmp($xm,$ym); } } @@ -286,6 +327,7 @@ Math::BigFloat - Arbitrary length float math package $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 $f->fcmp(NSTR) return CODE compare undef,<0,=0,>0 @@ -313,7 +355,7 @@ have embedded whitespace. An input parameter was "Not a Number" or divide by zero or sqrt of negative number. -=item Division is computed to +=item Division is computed to C<max($Math::BigFloat::div_scale,length(dividend)+length(divisor))> digits by default. @@ -352,5 +394,5 @@ as follows: =head1 AUTHOR Mark Biggar - +Patches by John Peacock Apr 2001 =cut |
