Intel® oneAPI Math Kernel Library Developer Reference - C
Computes the four-quadrant inverse tangent of the ratios of the corresponding elements of two vectors divided by π.
vsAtan2pi (n, a, b, y);
vsAtan2piI(n, a, inca, b, incb, y, incy);
vmsAtan2pi (n, a, b, y, mode);
vmsAtan2piI(n, a, inca, b, incb, y, incy, mode);
vdAtan2pi (n, a, b, y);
vdAtan2piI(n, a, inca, b, incb, y, incy);
vmdAtan2pi (n, a, b, y, mode);
vmdAtan2piI(n, a, inca, b, incb, y, incy, mode);
Name |
Type |
Description |
|---|---|---|
n |
const MKL_INT |
Specifies the number of elements to be calculated. |
a, b |
const float* for vsAtan2pi const float* for vmsAtan2pi const double* for vdAtan2pi const double* for vmdAtan2pi |
Pointers to the arrays containing the input vectors a and b. |
inca, incb, incy |
const MKL_INT |
Specifies increments for the elements of a, b and y. |
mode |
const MKL_INT64 |
Overrides the global VM mode setting for this function call. See vmlSetMode for possible values and their description. |
Name |
Type |
Description |
|---|---|---|
y |
float* for vsAtan2pi float* for vmsAtan2pi double* for vdAtan2pi double* for vmdAtan2pi |
Pointer to an array containing the output vector y. |
The v?Atan2pi function computes the four-quadrant inverse tangent of the ratios of the corresponding elements of two vectors divided by π.
For the elements of the output vector y, the function computers the four-quadrant arctangent of ai/bi, with the result divided by π.
| Argument 1 | Argument 2 | Result | Exception |
|---|---|---|---|
| -∞ | -∞ | -3/4 | |
| -∞ | x < +0 | -1/2 | |
| -∞ | -0 | +1/2 | |
| -∞ | +0 | -1/2 | |
| -∞ | x > +0 | -1/2 | |
| -∞ | +∞ | -1/4 | |
| x < +0 | -∞ | -1 | |
| x < +0 | -0 | -1/2 | |
| x < +0 | +0 | -1/2 | |
| x < +0 | +∞ | -0 | |
| -0 | -∞ | -1 | |
| -0 | x < +0 | -1 | |
| -0 | -0 | -1 | |
| -0 | +0 | -0 | |
| -0 | x > +0 | -0 | |
| -0 | +∞ | -0 | |
| +0 | -∞ | +1 | |
| +0 | x < +0 | +1 | |
| +0 | -0 | +1 | |
| +0 | +0 | +0 | |
| +0 | x > +0 | +0 | |
| +0 | +∞ | +0 | |
| x > +0 | -∞ | +1 | |
| x > +0 | -0 | +1/2 | |
| x > +0 | +0 | +1/2 | |
| x > +0 | +∞ | +1/4 | |
| +∞ | -∞ | +3/4 | |
| +∞ | x < +0 | +1/2 | |
| +∞ | -0 | +1/2 | |
| +∞ | +0 | +1/2 | |
| +∞ | x > +0 | +1/2 | |
| +∞ | +∞ | +1/4 | |
| x > +0 | QNAN | QNAN | |
| x > +0 | SNAN | QNAN | INVALID |
| QNAN | x > +0 | QNAN | |
| SNAN | x > +0 | QNAN | INVALID |
| QNAN | QNAN | QNAN | |
| QNAN | SNAN | QNAN | INVALID |
| SNAN | QNAN | QNAN | INVALID |
| SNAN | SNAN | QNAN | INVALID |