Function atan2

Element-wise arc tangent of y/x with correct quadrant.

Returns the angle in radians between the positive x-axis and the point (x, y). The result is in the range [-π, π].

Uses numerically stable formulas:

• When x >= 0: atan2(y, x) = 2 * atan(y / (sqrt(x^2 + y^2) + x))
• When x < 0: atan2(y, x) = 2 * atan((sqrt(x^2 + y^2) - x) / y)

The output is ill-defined when both x and y are zero.