## 3.12. __nv_atan2f

Prototype:

```float @__nv_atan2f(float %x, float %y)

```

Description:

Calculate the principal value of the arc tangent of the ratio of first and second input arguments x / y. The quadrant of the result is determined by the signs of inputs x and y.

Returns:

Result will be in radians, in the interval [- $\pi$ /, + $\pi$ ].
• __nv_atan2f(0, 1) returns +0.

Note:

For accuracy information for this function see the CUDA C++ Programming Guide, Appendix E.1, Table 6.

Library Availability:

Compute 2.0: Yes

Compute 3.0: Yes

Compute 3.5: Yes