PHP/Math/deg2rad

float deg2rad ( float num ) converts degrees to radians.

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$sin1 = sin(deg2rad(80));

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Return the distance between two locations in either kilometers or miles

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<?php define("KM", 6364.963); define("MILES", 3955.00465); function GetDistance($la1, $lo1, $la2, $lo2, $r = KM) {

 $l1 = deg2rad($la1);
 $l2 = deg2rad($la2);
 $dg = deg2rad($lo2 - $lo1);
 $d = $r * acos(sin($l1) * sin($l2) + cos($l1) * cos($l2) * cos($dg));
 return $d;

} $lat1 = 55; $long1 = 12; $lat2 = 34; $long2 = -118; echo "The distance from Copenhagen to Los Angeles is " . round(GetDistance($lat1, $long1, $lat2, $long2)) . " km\n"; echo "The distance from Copenhagen to Los Angeles is " . round(GetDistance($lat1, $long1, $lat2, $long2, MILES)) . " miles\n"; ?>

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