diff options
Diffstat (limited to 'contrib/perl5/lib/Math')
| -rw-r--r-- | contrib/perl5/lib/Math/BigFloat.pm | 57 | ||||
| -rw-r--r-- | contrib/perl5/lib/Math/BigInt.pm | 89 | ||||
| -rw-r--r-- | contrib/perl5/lib/Math/Complex.pm | 188 | ||||
| -rw-r--r-- | contrib/perl5/lib/Math/Trig.pm | 32 |
4 files changed, 278 insertions, 88 deletions
diff --git a/contrib/perl5/lib/Math/BigFloat.pm b/contrib/perl5/lib/Math/BigFloat.pm index 03bc2f4e271c..d8d643ca3e31 100644 --- a/contrib/perl5/lib/Math/BigFloat.pm +++ b/contrib/perl5/lib/Math/BigFloat.pm @@ -9,10 +9,8 @@ use overload '+' => sub {new Math::BigFloat &fadd}, '-' => sub {new Math::BigFloat $_[2]? fsub($_[1],${$_[0]}) : fsub(${$_[0]},$_[1])}, -'<=>' => sub {new Math::BigFloat - $_[2]? fcmp($_[1],${$_[0]}) : fcmp(${$_[0]},$_[1])}, -'cmp' => sub {new Math::BigFloat - $_[2]? ($_[1] cmp ${$_[0]}) : (${$_[0]} cmp $_[1])}, +'<=>' => sub {$_[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 $_[2]? scalar fdiv($_[1],${$_[0]}) : @@ -28,9 +26,9 @@ qw( sub new { my ($class) = shift; my ($foo) = fnorm(shift); - panic("Not a number initialized to Math::BigFloat") if $foo eq "NaN"; bless \$foo, $class; } + sub numify { 0 + "${$_[0]}" } # Not needed, additional overhead # comparing to direct compilation based on # stringify @@ -76,6 +74,7 @@ sub fnorm; sub fsqrt; sub fnorm { #(string) return fnum_str local($_) = @_; s/\s+//g; # strip white space + no warnings; # $4 and $5 below might legitimately be undefined if (/^([+-]?)(\d*)(\.(\d*))?([Ee]([+-]?\d+))?$/ && "$2$4" ne '') { &norm(($1 ? "$1$2$4" : "+$2$4"),(($4 ne '') ? $6-length($4) : $6)); } else { @@ -159,7 +158,8 @@ sub fdiv #(fnum_str, fnum_str[,scale]) return fnum_str $scale = length($xm)-1 if (length($xm)-1 > $scale); $scale = length($ym)-1 if (length($ym)-1 > $scale); $scale = $scale + length($ym) - length($xm); - &norm(&round(Math::BigInt::bdiv($xm.('0' x $scale),$ym),$ym), + &norm(&round(Math::BigInt::bdiv($xm.('0' x $scale),$ym), + Math::BigInt::babs($ym)), $xe-$ye-$scale); } } @@ -219,7 +219,11 @@ sub ffround { #(fnum_str, scale) return fnum_str if ($xe < 1) { '+0E+0'; } elsif ($xe == 1) { - &norm(&round('+0',"+0".substr($xm,$[+1,1),"+10"), $scale); + # The first substr preserves the sign, passing a non- + # normalized "-0" to &round when rounding -0.006 (for + # example), purely so &round won't lose the sign. + &norm(&round(substr($xm,$[,1).'0', + "+0".substr($xm,$[+1,1),"+10"), $scale); } else { &norm(&round(substr($xm,$[,$xe), "+0".substr($xm,$[+$xe,1),"+10"), $scale); @@ -236,12 +240,13 @@ sub fcmp #(fnum_str, fnum_str) return cond_code if ($x eq "NaN" || $y eq "NaN") { undef; } else { + local($xm,$xe,$ym,$ye) = split('E', $x."E$y"); + if ($xm eq '+0' || $ym eq '+0') { + return $xm <=> $ym; + } ord($y) <=> ord($x) - || - ( local($xm,$xe,$ym,$ye) = split('E', $x."E$y"), - (($xe <=> $ye) * (substr($x,$[,1).'1') - || Math::BigInt::cmp($xm,$ym)) - ); + || ($xe <=> $ye) * (substr($x,$[,1).'1') + || Math::BigInt::cmp($xm,$ym); } } @@ -301,7 +306,7 @@ floats as =item number format canonical strings have the form /[+-]\d+E[+-]\d+/ . Input values can -have imbedded whitespace. +have embedded whitespace. =item Error returns 'NaN' @@ -310,9 +315,24 @@ negative number. =item Division is computed to -C<max($div_scale,length(dividend)+length(divisor))> digits by default. +C<max($Math::BigFloat::div_scale,length(dividend)+length(divisor))> +digits by default. Also used for default sqrt scale. +=item Rounding is performed + +according to the value of +C<$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 C<even> rounding. + =back =head1 BUGS @@ -320,6 +340,15 @@ Also used for default sqrt scale. 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 +C<$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 C<ffround> and in the C<%f> printf string, +as follows: + + printf "%.3f\n", $bigfloat->ffround(-3); + =head1 AUTHOR Mark Biggar diff --git a/contrib/perl5/lib/Math/BigInt.pm b/contrib/perl5/lib/Math/BigInt.pm index b61b88456934..a43969c2b232 100644 --- a/contrib/perl5/lib/Math/BigInt.pm +++ b/contrib/perl5/lib/Math/BigInt.pm @@ -4,10 +4,8 @@ use overload '+' => sub {new Math::BigInt &badd}, '-' => sub {new Math::BigInt $_[2]? bsub($_[1],${$_[0]}) : bsub(${$_[0]},$_[1])}, -'<=>' => sub {new Math::BigInt - $_[2]? bcmp($_[1],${$_[0]}) : bcmp(${$_[0]},$_[1])}, -'cmp' => sub {new Math::BigInt - $_[2]? ($_[1] cmp ${$_[0]}) : (${$_[0]} cmp $_[1])}, +'<=>' => sub {$_[2]? bcmp($_[1],${$_[0]}) : bcmp(${$_[0]},$_[1])}, +'cmp' => sub {$_[2]? ($_[1] cmp ${$_[0]}) : (${$_[0]} cmp $_[1])}, '*' => sub {new Math::BigInt &bmul}, '/' => sub {new Math::BigInt $_[2]? scalar bdiv($_[1],${$_[0]}) : @@ -18,6 +16,14 @@ use overload $_[2]? bpow($_[1],${$_[0]}) : bpow(${$_[0]},$_[1])}, 'neg' => sub {new Math::BigInt &bneg}, 'abs' => sub {new Math::BigInt &babs}, +'<<' => sub {new Math::BigInt + $_[2]? blsft($_[1],${$_[0]}) : blsft(${$_[0]},$_[1])}, +'>>' => sub {new Math::BigInt + $_[2]? brsft($_[1],${$_[0]}) : brsft(${$_[0]},$_[1])}, +'&' => sub {new Math::BigInt &band}, +'|' => sub {new Math::BigInt &bior}, +'^' => sub {new Math::BigInt &bxor}, +'~' => sub {new Math::BigInt &bnot}, qw( "" stringify @@ -258,9 +264,11 @@ sub bdiv { #(dividend: num_str, divisor: num_str) return num_str else { push(@x, 0); } - @q = (); ($v2,$v1) = ($y[-2] || 0, $y[-1]); + @q = (); ($v2,$v1) = @y[-2,-1]; + $v2 = 0 unless $v2; while ($#x > $#y) { - ($u2,$u1,$u0) = ($x[-3] || 0, $x[-2] || 0, $x[-1]); + ($u2,$u1,$u0) = @x[-3..-1]; + $u2 = 0 unless $u2; $q = (($u0 == $v1) ? 99999 : int(($u0*1e5+$u1)/$v1)); --$q while ($v2*$q > ($u0*1e5+$u1-$q*$v1)*1e5+$u2); if ($q) { @@ -328,6 +336,69 @@ sub bpow { #(num_str, num_str) return num_str } } +# compute x << y, y >= 0 +sub blsft { #(num_str, num_str) return num_str + &bmul($_[$[], &bpow(2, $_[$[+1])); +} + +# compute x >> y, y >= 0 +sub brsft { #(num_str, num_str) return num_str + &bdiv($_[$[], &bpow(2, $_[$[+1])); +} + +# compute x & y +sub band { #(num_str, num_str) return num_str + local($x,$y,$r,$m,$xr,$yr) = (&bnorm($_[$[]),&bnorm($_[$[+1]),0,1); + if ($x eq 'NaN' || $y eq 'NaN') { + 'NaN'; + } else { + while ($x ne '+0' && $y ne '+0') { + ($x, $xr) = &bdiv($x, 0x10000); + ($y, $yr) = &bdiv($y, 0x10000); + $r = &badd(&bmul(int $xr & $yr, $m), $r); + $m = &bmul($m, 0x10000); + } + $r; + } +} + +# compute x | y +sub bior { #(num_str, num_str) return num_str + local($x,$y,$r,$m,$xr,$yr) = (&bnorm($_[$[]),&bnorm($_[$[+1]),0,1); + if ($x eq 'NaN' || $y eq 'NaN') { + 'NaN'; + } else { + while ($x ne '+0' || $y ne '+0') { + ($x, $xr) = &bdiv($x, 0x10000); + ($y, $yr) = &bdiv($y, 0x10000); + $r = &badd(&bmul(int $xr | $yr, $m), $r); + $m = &bmul($m, 0x10000); + } + $r; + } +} + +# compute x ^ y +sub bxor { #(num_str, num_str) return num_str + local($x,$y,$r,$m,$xr,$yr) = (&bnorm($_[$[]),&bnorm($_[$[+1]),0,1); + if ($x eq 'NaN' || $y eq 'NaN') { + 'NaN'; + } else { + while ($x ne '+0' || $y ne '+0') { + ($x, $xr) = &bdiv($x, 0x10000); + ($y, $yr) = &bdiv($y, 0x10000); + $r = &badd(&bmul(int $xr ^ $yr, $m), $r); + $m = &bmul($m, 0x10000); + } + $r; + } +} + +# represent ~x as twos-complement number +sub bnot { #(num_str) return num_str + &bsub(-1,$_[$[]); +} + 1; __END__ @@ -350,6 +421,12 @@ Math::BigInt - Arbitrary size integer math package $i->bmod(BINT) return BINT modulus $i->bgcd(BINT) return BINT greatest common divisor $i->bnorm return BINT normalization + $i->blsft(BINT) return BINT left shift + $i->brsft(BINT) return (BINT,BINT) right shift (quo,rem) just quo if scalar + $i->band(BINT) return BINT bit-wise and + $i->bior(BINT) return BINT bit-wise inclusive or + $i->bxor(BINT) return BINT bit-wise exclusive or + $i->bnot return BINT bit-wise not =head1 DESCRIPTION diff --git a/contrib/perl5/lib/Math/Complex.pm b/contrib/perl5/lib/Math/Complex.pm index 5b69039afc07..1a47f4af5e63 100644 --- a/contrib/perl5/lib/Math/Complex.pm +++ b/contrib/perl5/lib/Math/Complex.pm @@ -8,9 +8,10 @@ require Exporter; package Math::Complex; +use 5.005_64; use strict; -use vars qw($VERSION @ISA @EXPORT %EXPORT_TAGS); +our($VERSION, @ISA, @EXPORT, %EXPORT_TAGS); my ( $i, $ip2, %logn ); @@ -65,9 +66,10 @@ use overload # Package "privates" # -my $package = 'Math::Complex'; # Package name -my $display = 'cartesian'; # Default display format -my $eps = 1e-14; # Epsilon +my $package = 'Math::Complex'; # Package name +my %DISPLAY_FORMAT = ('style' => 'cartesian', + 'polar_pretty_print' => 1); +my $eps = 1e-14; # Epsilon # # Object attributes (internal): @@ -160,7 +162,7 @@ sub new { &make } # For backward compatibility only. # sub cplx { my ($re, $im) = @_; - return $package->make($re, defined $im ? $im : 0); + return __PACKAGE__->make($re, defined $im ? $im : 0); } # @@ -171,7 +173,7 @@ sub cplx { # sub cplxe { my ($rho, $theta) = @_; - return $package->emake($rho, defined $theta ? $theta : 0); + return __PACKAGE__->emake($rho, defined $theta ? $theta : 0); } # @@ -179,21 +181,21 @@ sub cplxe { # # The number defined as pi = 180 degrees # -use constant pi => 4 * CORE::atan2(1, 1); +sub pi () { 4 * CORE::atan2(1, 1) } # # pit2 # # The full circle # -use constant pit2 => 2 * pi; +sub pit2 () { 2 * pi } # # pip2 # # The quarter circle # -use constant pip2 => pi / 2; +sub pip2 () { pi / 2 } # # deg1 @@ -201,14 +203,14 @@ use constant pip2 => pi / 2; # One degree in radians, used in stringify_polar. # -use constant deg1 => pi / 180; +sub deg1 () { pi / 180 } # # uplog10 # # Used in log10(). # -use constant uplog10 => 1 / CORE::log(10); +sub uplog10 () { 1 / CORE::log(10) } # # i @@ -835,7 +837,7 @@ sub acos { my $u = CORE::atan2(CORE::sqrt(1-$beta*$beta), $beta); my $v = CORE::log($alpha + CORE::sqrt($alpha*$alpha-1)); $v = -$v if $y > 0 || ($y == 0 && $x < -1); - return $package->make($u, $v); + return __PACKAGE__->make($u, $v); } # @@ -857,7 +859,7 @@ sub asin { my $u = CORE::atan2($beta, CORE::sqrt(1-$beta*$beta)); my $v = -CORE::log($alpha + CORE::sqrt($alpha*$alpha-1)); $v = -$v if $y > 0 || ($y == 0 && $x < -1); - return $package->make($u, $v); + return __PACKAGE__->make($u, $v); } # @@ -1153,34 +1155,53 @@ sub atan2 { # display_format # ->display_format # -# Set (fetch if no argument) display format for all complex numbers that +# Set (get if no argument) the display format for all complex numbers that # don't happen to have overridden it via ->display_format # -# When called as a method, this actually sets the display format for +# When called as an object method, this actually sets the display format for # the current object. # # Valid object formats are 'c' and 'p' for cartesian and polar. The first # letter is used actually, so the type can be fully spelled out for clarity. # sub display_format { - my $self = shift; - my $format = undef; + my $self = shift; + my %display_format = %DISPLAY_FORMAT; - if (ref $self) { # Called as a method - $format = shift; - } else { # Regular procedure call - $format = $self; - undef $self; + if (ref $self) { # Called as an object method + if (exists $self->{display_format}) { + my %obj = %{$self->{display_format}}; + @display_format{keys %obj} = values %obj; + } + if (@_ == 1) { + $display_format{style} = shift; + } else { + my %new = @_; + @display_format{keys %new} = values %new; + } + } else { # Called as a class method + if (@_ = 1) { + $display_format{style} = $self; + } else { + my %new = @_; + @display_format{keys %new} = values %new; + } + undef $self; } if (defined $self) { - return defined $self->{display} ? $self->{display} : $display - unless defined $format; - return $self->{display} = $format; + $self->{display_format} = { %display_format }; + return + wantarray ? + %{$self->{display_format}} : + $self->{display_format}->{style}; } - return $display unless defined $format; - return $display = $format; + %DISPLAY_FORMAT = %display_format; + return + wantarray ? + %DISPLAY_FORMAT : + $DISPLAY_FORMAT{style}; } # @@ -1195,12 +1216,12 @@ sub display_format { # sub stringify { my ($z) = shift; - my $format; - $format = $display; - $format = $z->{display} if defined $z->{display}; + my $style = $z->display_format; + + $style = $DISPLAY_FORMAT{style} unless defined $style; - return $z->stringify_polar if $format =~ /^p/i; + return $z->stringify_polar if $style =~ /^p/i; return $z->stringify_cartesian; } @@ -1220,17 +1241,27 @@ sub stringify_cartesian { if int(CORE::abs($y)) != int(CORE::abs($y) + $eps); $re = "$x" if CORE::abs($x) >= $eps; - if ($y == 1) { $im = 'i' } - elsif ($y == -1) { $im = '-i' } - elsif (CORE::abs($y) >= $eps) { $im = $y . "i" } + + my %format = $z->display_format; + my $format = $format{format}; + + if ($y == 1) { $im = 'i' } + elsif ($y == -1) { $im = '-i' } + elsif (CORE::abs($y) >= $eps) { + $im = (defined $format ? sprintf($format, $y) : $y) . "i"; + } my $str = ''; - $str = $re if defined $re; - $str .= "+$im" if defined $im; - $str =~ s/\+-/-/; - $str =~ s/^\+//; - $str =~ s/([-+])1i/$1i/; # Not redundant with the above 1/-1 tests. - $str = '0' unless $str; + $str = defined $format ? sprintf($format, $re) : $re + if defined $re; + if (defined $im) { + if ($y < 0) { + $str .= $im; + } elsif ($y > 0) { + $str .= "+" if defined $re; + $str .= $im; + } + } return $str; } @@ -1277,6 +1308,8 @@ sub stringify_polar { return '[0,0]' if $r <= $eps; + my %format = $z->display_format; + my $nt = $t / pit2; $nt = ($nt - int($nt)) * pit2; $nt += pit2 if $nt < 0; # Range [0, 2pi] @@ -1299,7 +1332,7 @@ sub stringify_polar { $nt -= pit2 if $nt > pi; - if (CORE::abs($nt) >= deg1) { + if ($format{polar_pretty_print} && CORE::abs($nt) >= deg1) { my ($n, $k, $kpi); for ($k = 1, $kpi = pi; $k < 10; $k++, $kpi += pi) { @@ -1328,12 +1361,19 @@ sub stringify_polar { if ($theta !~ m(^-?\d*pi/\d+$) and int(CORE::abs($theta)) != int(CORE::abs($theta) + $eps)); + my $format = $format{format}; + if (defined $format) { + $r = sprintf($format, $r); + $theta = sprintf($format, $theta); + } + return "\[$r,$theta\]"; } 1; __END__ +=pod =head1 NAME Math::Complex - complex numbers and associated mathematical functions @@ -1617,9 +1657,9 @@ It is possible to write: $x = cplxe(-3, pi/4); -but that will be silently converted into C<[3,-3pi/4]>, since the modulus -must be non-negative (it represents the distance to the origin in the complex -plane). +but that will be silently converted into C<[3,-3pi/4]>, since the +modulus must be non-negative (it represents the distance to the origin +in the complex plane). It is also possible to have a complex number as either argument of either the C<make> or C<emake>: the appropriate component of @@ -1631,31 +1671,67 @@ the argument will be used. =head1 STRINGIFICATION When printed, a complex number is usually shown under its cartesian -form I<a+bi>, but there are legitimate cases where the polar format +style I<a+bi>, but there are legitimate cases where the polar style I<[r,t]> is more appropriate. -By calling the routine C<Math::Complex::display_format> and supplying either -C<"polar"> or C<"cartesian">, you override the default display format, -which is C<"cartesian">. Not supplying any argument returns the current -setting. +By calling the class method C<Math::Complex::display_format> and +supplying either C<"polar"> or C<"cartesian"> as an argument, you +override the default display style, which is C<"cartesian">. Not +supplying any argument returns the current settings. This default can be overridden on a per-number basis by calling the C<display_format> method instead. As before, not supplying any argument -returns the current display format for this number. Otherwise whatever you -specify will be the new display format for I<this> particular number. +returns the current display style for this number. Otherwise whatever you +specify will be the new display style for I<this> particular number. For instance: use Math::Complex; Math::Complex::display_format('polar'); - $j = ((root(1, 3))[1]; - print "j = $j\n"; # Prints "j = [1,2pi/3] + $j = (root(1, 3))[1]; + print "j = $j\n"; # Prints "j = [1,2pi/3]" $j->display_format('cartesian'); print "j = $j\n"; # Prints "j = -0.5+0.866025403784439i" -The polar format attempts to emphasize arguments like I<k*pi/n> -(where I<n> is a positive integer and I<k> an integer within [-9,+9]). +The polar style attempts to emphasize arguments like I<k*pi/n> +(where I<n> is a positive integer and I<k> an integer within [-9,+9]), +this is called I<polar pretty-printing>. + +=head2 CHANGED IN PERL 5.6 + +The C<display_format> class method and the corresponding +C<display_format> object method can now be called using +a parameter hash instead of just a one parameter. + +The old display format style, which can have values C<"cartesian"> or +C<"polar">, can be changed using the C<"style"> parameter. (The one +parameter calling convention also still works.) + +There are two new display parameters. + +The first one is C<"format">, which is a sprintf()-style format +string to be used for both parts of the complex number(s). The +default is C<undef>, which corresponds usually (this is somewhat +system-dependent) to C<"%.15g">. You can revert to the default by +setting the format string to C<undef>. + + # the $j from the above example + + $j->display_format('format' => '%.5f'); + print "j = $j\n"; # Prints "j = -0.50000+0.86603i" + $j->display_format('format' => '%.6f'); + print "j = $j\n"; # Prints "j = -0.5+0.86603i" + +Notice that this affects also the return values of the +C<display_format> methods: in list context the whole parameter hash +will be returned, as opposed to only the style parameter value. If +you want to know the whole truth for a complex number, you must call +both the class method and the object method: + +The second new display parameter is C<"polar_pretty_print">, which can +be set to true or false, the default being true. See the previous +section for what this means. =head1 USAGE @@ -1746,7 +1822,7 @@ Whatever it is, it does not manifest itself anywhere else where Perl runs. =head1 AUTHORS -Raphael Manfredi <F<Raphael_Manfredi@grenoble.hp.com>> and +Raphael Manfredi <F<Raphael_Manfredi@pobox.com>> and Jarkko Hietaniemi <F<jhi@iki.fi>>. Extensive patches by Daniel S. Lewart <F<d-lewart@uiuc.edu>>. diff --git a/contrib/perl5/lib/Math/Trig.pm b/contrib/perl5/lib/Math/Trig.pm index 924286d20491..492706cd6aa8 100644 --- a/contrib/perl5/lib/Math/Trig.pm +++ b/contrib/perl5/lib/Math/Trig.pm @@ -7,13 +7,12 @@ require Exporter; package Math::Trig; +use 5.005_64; use strict; use Math::Complex qw(:trig); -use vars qw($VERSION $PACKAGE - @ISA - @EXPORT @EXPORT_OK %EXPORT_TAGS); +our($VERSION, $PACKAGE, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS); @ISA = qw(Exporter); @@ -37,8 +36,8 @@ my @rdlcnv = qw(cartesian_to_cylindrical %EXPORT_TAGS = ('radial' => [ @rdlcnv ]); -use constant pi2 => 2 * pi; -use constant pip2 => pi / 2; +sub pi2 () { 2 * pi } # use constant generates warning +sub pip2 () { pi / 2 } # use constant generates warning use constant DR => pi2/360; use constant RD => 360/pi2; use constant DG => 400/360; @@ -133,11 +132,11 @@ Math::Trig - trigonometric functions =head1 SYNOPSIS use Math::Trig; - + $x = tan(0.9); $y = acos(3.7); $z = asin(2.4); - + $halfpi = pi/2; $rad = deg2rad(120); @@ -259,7 +258,7 @@ complex numbers as results because the C<Math::Complex> takes care of details like for example how to display complex numbers. For example: print asin(2), "\n"; - + should produce something like this (take or leave few last decimals): 1.5707963267949-1.31695789692482i @@ -273,10 +272,10 @@ and the imaginary part of approximately C<-1.317>. $radians = deg2rad($degrees); $radians = grad2rad($gradians); - + $degrees = rad2deg($radians); $degrees = grad2deg($gradians); - + $gradians = deg2grad($degrees); $gradians = rad2grad($radians); @@ -409,7 +408,16 @@ To calculate the distance between London (51.3N 0.5W) and Tokyo (35.7N $km = great_circle_distance(@L, @T, 6378); The answer may be off by few percentages because of the irregular -(slightly aspherical) form of the Earth. +(slightly aspherical) form of the Earth. The used formula + + lat0 = 90 degrees - phi0 + lat1 = 90 degrees - phi1 + d = R * arccos(cos(lat0) * cos(lat1) * cos(lon1 - lon01) + + sin(lat0) * sin(lat1)) + +is also somewhat unreliable for small distances (for locations +separated less than about five degrees) because it uses arc cosine +which is rather ill-conditioned for values close to zero. =head1 BUGS @@ -426,7 +434,7 @@ an answer instead of giving a fatal runtime error. =head1 AUTHORS Jarkko Hietaniemi <F<jhi@iki.fi>> and -Raphael Manfredi <F<Raphael_Manfredi@grenoble.hp.com>>. +Raphael Manfredi <F<Raphael_Manfredi@pobox.com>>. =cut |