CONST pi = 3.141593     ' define pi
CONST radio = 6372.8    ' radio de la tierra en km

PRINT : PRINT " Distancia de Haversine:";
PRINT Haversine!(36.12, -86.67, 33.94, -118.4); "km"
END

FUNCTION Haversine! (lat1!, long1!, lat2!, long2!)
    deg2rad! = pi / 180    ' define grados a radianes 0.01745..

    dLong! = deg2rad! * (long1! - long2!)
    theta1! = deg2rad! * lat1!
    theta2! = deg2rad! * lat2!
    dx! = COS(dLong!) * COS(theta1!) - COS(theta2!)
    dy! = SIN(dLong!) * COS(theta1!)
    dz! = SIN(theta1!) - SIN(theta2!)

    Haversine! = (SQR(dx! * dx! + dy! * dy! + dz! * dz!) / 2) * radio * 2
END FUNCTION