($latitude,$longitude)=ll(
MILES=>5,
LATITUDE=>51+29/60,
LONGITUDE=>0+0/60,
DIRECTION=>315,
);
if( $latitude < 0 ){
$latitude *= -1;
$ns='S';
}else{
$ns='N';
}
if( $longitude < 0 ){
$longitude *= -1;
$ew='W';
}else{
$ew='E';
}
print int $latitude,"°",60*($latitude-int $latitude),"' $ns\n",
int $longitude,"°",60*($longitude-int $longitude),"' $ew\n";
use Math::Trig;
sub ll{
my %l=@_;
use constant PI=>4*atan2(1,1);
my $nm = $l{MILES}*.87;
my $A=$l{DIRECTION}*PI/180;
my $b=(90-$l{LATITUDE})*PI/180;
my $c=$nm/60/180*PI;
my $a=acos(cos($b)*cos($c)+sin($b)*sin($c)*cos($A));
my $latitude=90-180/PI*$a;
my $C=asin(sin($c)*sin($A)/sin($a));
my $longitude=$l{LONGITUDE}+180/PI*$C;
return $latitude,$longitude;
}