Calculate arcus tangent defined on whole circle.
| a | The denumerator. |
| b | The numerator. |
| return value | The corrected angle atan(b/a). |
Based on signs of a and b, the exact quarter of the circle for the angle can be calculated. Theatan2 calculates atan(b/a), and corrects its angle.
The arguments can only be real numbers or quantities with same unit.
atan2(-1, -1) as degrees