#!/usr/bin/perl -lw

use strict;

use Time::HiRes "gettimeofday";

use POSIX "fmod";

use Math::Complex;

my $pi = 3.141592653589793238462643383279502884197169399375105820974;

my $step = $pi / 10000;

sub mycos {

my $x = abs(shift() / $pi);

$x ** $x * Re(cplx(-$x) ** -$x);

}

my ($a, $b, $c, $d);

($a, $b) = gettimeofday;

for (my $i = 0; $i < 2 * $pi; $i += $step) {

my $x = cos($i);

}

($c, $d) = gettimeofday;

my $ta = ($c-$a+($d-$b)/1000000);

print "cos() took: $ta seconds";

($a, $b) = gettimeofday;

for (my $i = 0; $i < 2 * $pi; $i += $step) {

my $c = mycos($i);

}

($c, $d) = gettimeofday;

my $tb = ($c-$a+($d-$b)/1000000);

print "mycos() took: $tb seconds";

print "mycos() takes approximately ".($tb/$ta)." times longer to run than cos()";

print "sanity:";

for (my $i = 0; $i <= 2 * $pi; $i += 1) {

printf "cos (%.15f): \t%+.15f\n", $i, cos($i);

printf "mycos(%.15f): \t%+.15f\n", $i, mycos($i);

}