Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 7/13/2023
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

v?Log2

Computes the base 2 logarithm of vector elements.

Syntax

call vslog2 (n, a, y)

call vslog2i(n, a, inca, y, incy)

call vmslog2 (n, a, y, mode)

call vmslog2i(n, a, inca, y, incy, mode)

call vdlog2 (n, a, y)

call vdlog2i(n, a, inca, y, incy)

call vmdlog2 (n, a, y, mode)

call vmdlog2i(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 vslog2

REAL for vmslog2

DOUBLE PRECISION for vdlog2

DOUBLE PRECISION for vmdlog2

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 vslog2

REAL for vmslog2

DOUBLE PRECISION for vdlog2

DOUBLE PRECISION for vmdlog2

Pointer to an array containing the output vector y.

Description

The v?Log2 function computes the base 2 logarithm of vector elements.

See Special Value Notations for the conventions used in this table:

Special values for Real Function v?Log2(x)
Argument Result VM Error Status Exception
+1 +0    
x < +0 QNAN VML_STATUS_ERRDOM INVALID
+0 - VML_STATUS_SING ZERODIVIDE
-0 - VML_STATUS_SING ZERODIVIDE
- QNAN VML_STATUS_ERRDOM INVALID
+ +    
QNAN QNAN    
SNAN QNAN   INVALID

See Also