Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 7/13/2023
Public

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v?Tanpi

Computes the tangent of vector elements multiplied by π.

Syntax

call vstanpi (n, a, y)

call vstanpii(n, a, inca, y, incy)

call vmstanpi (n, a, y, mode)

call vmstanpii(n, a, inca, y, incy, mode)

call vdtanpi (n, a, y)

call vdtanpii(n, a, inca, y, incy)

call vmdtanpi (n, a, y, mode)

call vmdtanpii(n, a, inca, y, incy, mode)

Include Files

  • mkl_vml.f90

Input Parameters

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.

inca, incy

INTEGER, INTENT(IN)

Specifies increments for the elements of a and y.

mode

INTEGER (KIND=8)

Overrides the global VM mode setting for this function call. See vmlSetMode for possible values and their description.

Output Parameters

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.

Description

The v?Tanpi function computes the tangent of vector elements multiplied by π. For an argument x, the function computes tan(π*x).

Special values for Real Function v?Tanpi(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.

Application Notes

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.

See Also