Computes four-quadrant inverse tangent of elements of two vectors.
FORTRAN:
call vsatan2( n, a, b, y )
call vmsatan2( n, a, b, y, mode )
call vdatan2( n, a, b, y )
call vmdatan2( n, a, b, y, mode )
C:
vsAtan2( n, a, b, y );
vmsAtan2( n, a, b, y, mode );
vdAtan2( n, a, b, y );
vmdAtan2( n, a, b, y, mode );
Name |
Type |
Description |
|---|---|---|
n |
FORTRAN 77: INTEGER Fortran 90: INTEGER, INTENT(IN) C: const int |
Specifies the number of elements to be calculated. |
a, b |
FORTRAN 77: REAL for vsatan2, vmsatan2 DOUBLE PRECISION for vdatan2, vmdatan2 Fortran 90: REAL, INTENT(IN) for vsatan2, vmsatan2 DOUBLE PRECISION, INTENT(IN) for vdatan2, vmdatan2 C: const float* for vsAtan2, vmsAtan2 const double* for vdAtan2, vmdAtan2 |
FORTRAN: Arrays that specify the input vectors a and b. C: Pointers to arrays that contain the input vectors a and b. |
mode |
FORTRAN 77: INTEGER*8 Fortran 90: INTEGER(KIND=8), INTENT(IN) C: const MKL_INT64 |
Overrides global VML mode setting for this function call. See vmlSetMode for possible values and their description. |
Name |
Type |
Description |
|---|---|---|
y |
FORTRAN 77: REAL for vsatan2, vmsatan2 DOUBLE PRECISION for vdatan2, vmdatan2 Fortran 90: REAL, INTENT(OUT) for vsatan2, vmsatan2 DOUBLE PRECISION, INTENT(OUT) for vdatan2, vmdatan2 C: float* for vsAtan2, vmsAtan2 double* for vdAtan2, vmdAtan2 |
FORTRAN: Array that specifies the output vector y. C: Pointer to an array that contains the output vector y. |
The v?Atan2 function computes four-quadrant inverse tangent of elements of two vectors.
The elements of the output vectory are computed as the four-quadrant arctangent of a[i] / b[i].
| Argument 1 | Argument 2 | Result | Exception |
|---|---|---|---|
| -∞ | -∞ | -3*π/4 | |
| -∞ | X < +0 | -π/2 | |
| -∞ | -0 | -π/2 | |
| -∞ | +0 | -π/2 | |
| -∞ | X > +0 | -π/2 | |
| -∞ | +∞ | -π/4 | |
| X < +0 | -∞ | -π | |
| X < +0 | -0 | -π/2 | |
| X < +0 | +0 | -π/2 | |
| X < +0 | +∞ | -0 | |
| -0 | -∞ | -π | |
| -0 | X < +0 | -π | |
| -0 | -0 | -π | |
| -0 | +0 | -0 | |
| -0 | X > +0 | -0 | |
| -0 | +∞ | -0 | |
| +0 | -∞ | +π | |
| +0 | X < +0 | +π | |
| +0 | -0 | +π | |
| +0 | +0 | +0 | |
| +0 | X > +0 | +0 | |
| +0 | +∞ | +0 | |
| X > +0 | -∞ | +π | |
| X > +0 | -0 | +π/2 | |
| X > +0 | +0 | +π/2 | |
| X > +0 | +∞ | +0 | |
| +∞ | -∞ | -3*π/4 | |
| +∞ | X < +0 | +π/2 | |
| +∞ | -0 | +π/2 | |
| +∞ | +0 | +π/2 | |
| +∞ | X > +0 | +π/2 | |
| +∞ | +∞ | +π/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 |