v?Powr

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 3/31/2023

Version

Public

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v?Powr

Computes a to the power b for elements of two vectors, where the elements of vector argument a are all non-negative.

Syntax

call vspowr (n, a, b, y )

call vspowri(n, a, inca, b, incb, y, incy)

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

call vmspowri(n, a, inca, b, incb, y, incy, mode)

call vdpowr (n, a, b, y )

call vdpowri(n, a, inca, b, incb, y, incy)

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

call vmdpowri(n, a, inca, b, incb, y, incy, mode)

Include Files

mkl_vml.f90

Input Parameters

Name	Type	Description
`n`	INTEGER	Specifies the number of elements to be calculated.
`a, b`	REAL for vsPowr REAL for vmsPowr DOUBLE PRECISION for vdPowr DOUBLE PRECISION for vmdPowr	Pointers to arrays containing the input vectors `a` and `b`.
inca, incb, incy	INTEGER, INTENT(IN)	Specifies increments for the elements of `a`, `b`, 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 vsPowr REAL for vmsPowr DOUBLE PRECISION for vdPowr DOUBLE PRECISION for vmdPowr	Pointer to an array containing the output vector `y`.

Name

Type

Description

y

REAL for vsPowr

REAL for vmsPowr

DOUBLE PRECISION for vdPowr

DOUBLE PRECISION for vmdPowr

Pointer to an array containing the output vector y.

Description

The v?Powr function raises each element of vector a by the corresponding element of vector b. The elements of a are all nonnegative (a_i≥ 0).

Precision Overflow Thresholds for Real Function v?Powr
Data Type	Threshold Limitations on Input Parameters
single precision	`a`_i < (FLT_MAX)^1/b_i
double precision	`a`_i < (DBL_MAX)^1/b_i

Special values and VM Error Status treatment for v?Powr function are the same as for v?Pow, unless otherwise indicated in this table:

Special values for Real Function v?Powr(x)
Argument 1	Argument 2	Result	VM Error Status	Exception
`x` < 0	any value `y`	NAN	VML_STATUS_ERRDOM	INVALID
0 < `x` < ∞	±0	1
±0	-∞ < `y` < 0	+∞
±0	-∞	+∞
±0	`y` > 0	+0
1	-∞ < `y` < ∞	1
±0	±0	NAN
+∞	±0	NAN
1	+∞	NAN
`x`≥ 0	NAN	NAN
NAN	any value `y`	NAN
0 < `x` <1	-∞	+∞
`x` > 1	-∞	+0
0 ≤`x` < 1	+∞	+0
`x` > 1	+∞	+∞
+∞	`x` < +0	+0
+∞	`x` > +0	+∞
QNAN	QNAN	QNAN	VML_STATUS_ERRDOM
QNAN	SNAN	QNAN	VML_STATUS_ERRDOM	INVALID
SNAN	QNAN	QNAN	VML_STATUS_ERRDOM	INVALID
SNAN	SNAN	QNAN	VML_STATUS_ERRDOM	INVALID

Parent topic: Power and Root Functions

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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