Intel® Math Kernel Library 2019 Developer Reference - Fortran

v?Powx

Computes vector a to the scalar power b.

Syntax

call vspowx( n, a, b, y )

call vmspowx( n, a, b, y, mode )

call vdpowx( n, a, b, y )

call vmdpowx( n, a, b, y, mode )

call vcpowx( n, a, b, y )

call vmcpowx( n, a, b, y, mode )

call vzpowx( n, a, b, y )

call vmzpowx( n, a, b, y, mode )

Include Files

Input Parameters

Name

Type

Description

n

INTEGER, INTENT(IN)

Number of elements to be calculated.

a

DOUBLE PRECISION for vdpowx, vmdpowx

COMPLEX for vcpowx, vmcpowx

DOUBLE COMPLEX for vzpowx, vmzpowx

REAL, INTENT(IN) for vspowx, vmspowx

DOUBLE PRECISION, INTENT(IN) for vdpowx, vmdpowx

COMPLEX, INTENT(IN) for vcpowx, vmcpowx

DOUBLE COMPLEX, INTENT(IN) for vzpowx, vmzpowx

Array a that specifies the input vector

b

DOUBLE PRECISION for vdpowx, vmdpowx

COMPLEX for vcpowx, vmcpowx

DOUBLE COMPLEX for vzpowx, vmzpowx

REAL, INTENT(IN) for vspowx, vmspowx

DOUBLE PRECISION, INTENT(IN) for vdpowx, vmdpowx

COMPLEX, INTENT(IN) for vcpowx, vmcpowx

DOUBLE COMPLEX, INTENT(IN) for vzpowx, vmzpowx

Scalar value b that is the constant power.

mode

INTEGER(KIND=8), INTENT(IN)

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

Precision Overflow Thresholds for Real v?Powx Function
Data Type Threshold Limitations on Input Parameters
single precision abs(a[i]) < ( FLT_MAX )1/b
double precision abs(a[i]) < ( DBL_MAX )1/b

Precision overflow thresholds for the complex v?Powx function are beyond the scope of this document.

Output Parameters

Name

Type

Description

y

DOUBLE PRECISION for vdpowx, vmdpowx

COMPLEX for vcpowx, vmcpowx

DOUBLE COMPLEX for vzpowx, vmzpowx

REAL, INTENT(OUT) for vspowx, vmspowx

DOUBLE PRECISION, INTENT(OUT) for vdpowx, vmdpowx

COMPLEX, INTENT(OUT) for vcpowx, vmcpowx

DOUBLE COMPLEX, INTENT(OUT) for vzpowx, vmzpowx

Array that specifies the output vector y.

Description

The v?Powx function computes a to the power b for a vector a and a scalar b.

The real function v(s/d)Powx has certain limitations on the input range of a and b parameters. Specifically, if a[i] is positive, then b may be arbitrary. For negative a[i], the value of b must be an integer (either positive or negative).

The complex function v(c/z)Powx has no input range limitations.

Special values and VM Error Status treatment are the same as for the v?Pow function.