Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 3/31/2023
Public

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v?Cospi

Computes the cosine of vector elements multiplied by π.

Syntax

call vscospi (n, a, y)

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

call vmscospi (n, a, y, mode)

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

call vdcospi (n, a, y)

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

call vmdcospi (n, a, y, mode)

call vmdcospii(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 vscospi

REAL for vmscospi

DOUBLE PRECISION for vdcospi

DOUBLE PRECISION for vmdcospi

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 vscospi

REAL for vmscospi

DOUBLE PRECISION for vdcospi

DOUBLE PRECISION for vmdcospi

Pointer to an array containing the output vector y.

Description

The v?Cospi function computes the cosine of vector elements multiplied by π. For an argument x, the function computes cos(π*x).

Special values for Real Function v?Cospi(x)
Argument Result VM Error Status Exception
+0 +1    
-0 +1    
n + 0.5, for any integer n where n + 0.5 is representable +0    
± QNAN VML_STATUS_ERRDOM INVALID
QNAN QNAN    
SNAN QNAN   INVALID
Application Notes

If arguments abs(ai) ≤ 222 for single precision or abs(ai ) ≤ 243 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