Returns the vector's angle in radians with respect to the X axis, or [code](1, 0)[/code] vector.
- Equivalent to the result of [method @GDScript.atan2] when called with the vector's [member x] and [member y] as parameters: [code]atan2(x, y)[/code].
+ Equivalent to the result of [method @GDScript.atan2] when called with the vector's [member y] and [member x] as parameters: [code]atan2(y, x)[/code].