Intel® Math Kernel Library 2019 Developer Reference - Fortran
Computes the tangent of vector elements multiplied by π.
call vstanpi (n, a, y)
call vmstanpi (n, a, y, mode)
call vdtanpi (n, a, y)
call vmdtanpi (n, a, y, mode)
Name |
Type |
Description |
|---|---|---|
n |
INTEGER |
Specifies the number of elements to be calculated. |
a |
REAL for vstanpi REAL for vmstanpi DOUBLE PRECISION for vdtanpi DOUBLE PRECISION for vmdtanpi |
Pointer to the array containing the input vector a. |
mode |
INTEGER (KIND=8) |
Overrides the global VM mode setting for this function call. See vmlSetMode for possible values and their description. |
Name |
Type |
Description |
|---|---|---|
y |
REAL for vstanpi REAL for vmstanpi DOUBLE PRECISION for vdtanpi DOUBLE PRECISION for vmdtanpi |
Pointer to an array containing the output vector y. |
The v?Tanpi function computes the tangent of vector elements multiplied by π. For an argument x, the function computes tan(π*x).
| Argument | Result | VM Error Status | Exception |
|---|---|---|---|
| +0 | +1 | ||
| -0 | +1 | ||
| ±∞ | QNAN | VML_STATUS_ERRDOM | INVALID |
| n, even integer | copysign(0.0, n) | ||
| n, odd integer | copysign(0.0, -n) | ||
| n + 0.5, for n even integer and n + 0.5 representable | +∞ | ||
| n + 0.5, for n odd integer and n + 0.5 representable | -∞ | ||
| QNAN | QNAN | ||
| SNAN | QNAN | INVALID |
The copysign(x, y) function returns the first vector argument x with the sign changed to match that of the second argument y.
If arguments abs(ai) ≤ 2 13 for single precision or abs(ai ) ≤ 2 67 for double precision, they belong to the fast computational path: arguments for which VM provides the best possible performance. Avoid arguments with do not belong to the fast computational path in VM High Accuracy (HA) or Low Accuracy (LA) functions. For arguments which do not belong to the fast computational path you can use VM Enhanced Performance (EP) functions, which are fast on the entire function domain. However, these functions provide lower accuracy.