Visible to Intel only — GUID: GUID-A1B2EC50-F5AE-446C-B349-5FD3F36AF9CF
Visible to Intel only — GUID: GUID-A1B2EC50-F5AE-446C-B349-5FD3F36AF9CF
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:
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 |