Skip to content

    ArcTan2

    Return arctangent of (y/x).

    Declaration

    Source position: math.pp line 542

    function ArcTan2(y: Float; x: Float) : Float;

    Description

    arctan2 calculates arctan(y/x), and returns an angle in the correct quadrant. The returned angle will be in the range $-\pi$ to $\pi$ radians. The values of x and y must be between -2\^{}64 and 2\^{}64, moreover x should be different from zero. On Intel systems this function is implemented with the native intel fpatan instruction.

    See also

    Name Description
    arccos Return inverse cosine.
    arcosh Return inverse hyperbolic cosine.
    arsinh Return inverse hyperbolic sine.
    artanh Return inverse hyperbolic tangent.

    Example

    Program Example6;

{ Program to demonstrate the arctan2 function. }

Uses math;

  Procedure WriteRadDeg(X : float);

  begin
    Writeln(X:8:5,' rad = ',radtodeg(x):8:5,' degrees.')
  end;

begin
  WriteRadDeg (arctan2(2,1));
end.