PlanetsCentral

ATan(x:Num, [y:Num]):Num

Returns the arc-tangent of x resp. x/y. The angle is returned in degrees (not radians as many other programming languages), and is in the range [0,360).

A heading angle is computed as

  angle := ATan(Waypoint.DX, Waypoint.DY)

This form is better than

  angle := ATan(Waypoint.DX / Waypoint.DY)

because it gets the quadrant right, and does not divide by zero if Waypoint.DX is 0.

If any parameter is EMPTY, or if both parameters are 0, returns EMPTY.

See also: Elementary Functions