lz_arctangent2
The angle of the point (x, y), with y first, as C's atan2 takes them.
long lz_arctangent2( CLZNumber* leftOperand, CLZNumber* rightOperand, CLZNumber* targetNumber = nullptr );The angle of the point from the positive x-axis, in (−π, π], or (−180°, 180°], correctly rounded in the thread's unit. The left operand is y and the right is x, as C's atan2( y, x ) takes them.
On the axes it answers as std::atan2 does for +0: nought along the positive x-axis, π along the negative one, and ±π/2 on the y-axis. The origin answers nought. An infinity or a not-a-number in either answers a not-a-number, and a missing operand is refused, kFailed. A right operand in another base is brought into the left's exactly.
Examples
| Call | Answer |
|---|---|
lz_arctangent2( 1, 1 ) | 0.785398163397448309615660845819875721 |
lz_arctangent2( 1, −1 ) degrees | 135 |
lz_arctangent2( −1, −1 ) degrees | −135 |
lz_arctangent2( 0, −1 ) | 3.141592653589793238462643383279502884 |
lz_arctangent2( 0, 0 ) | 0 |
Each answer is what Addaptic printed for the call, in radians, at 36 places unless a setting is shown.
Returns
kNoError (0) when the answer is written. Otherwise an error code, with the answer flagged infinite or not-a-number; see Errors and flags.
See also
lz_arctangentThe angle whose tangent is the number.lzc_argThe argument of a complex number, its angle, a real answer in the thread's angle unit.