MathF.Atan2(Single, Single) Method

Definition

Returns the angle whose tangent is the quotient of two specified numbers.

public:
 static float Atan2(float y, float x);
public static float Atan2 (float y, float x);
static member Atan2 : single * single -> single
Public Shared Function Atan2 (y As Single, x As Single) As Single

Parameters

y
Single

The y coordinate of a point.

x
Single

The x coordinate of a point.

Returns

An angle, θ, measured in radians, such that -π ≤ θ ≤ π, and tan(θ) = y / x, where (x, y) is a point in the Cartesian plane. Observe the following:

  • For (x, y) in quadrant 1, 0 < θ < π/2.

  • For (x, y) in quadrant 2, π/2 < θ ≤ π.

  • For (x, y) in quadrant 3, -π < θ < -π/2.

  • For (x, y) in quadrant 4, -π/2 < θ < 0.

For points on the boundaries of the quadrants, the return value is the following:

  • If y is 0 and x is not negative, θ = 0.

  • If y is 0 and x is negative, θ = π.

  • If y is positive and x is 0, θ = π/2.

  • If y is negative and x is 0, θ = -π/2.

  • If y is 0 and x is 0, θ = 0.

If x or y is NaN, or if x and y are either PositiveInfinity or NegativeInfinity, the method returns NaN.

Remarks

The return value is the angle in the Cartesian plane formed by the x-axis, and a vector starting from the origin, (0,0), and terminating at the point, (x,y).

Applies to