Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
v?LGamma
Computes the natural logarithm of the absolute value of gamma function for vector elements.
Syntax
call vslgamma ( n , a , y )
call vslgammai(n, a, inca, y, incy)
call vmslgamma ( n , a , y , mode )
call vmslgammai(n, a, inca, y, incy, mode)
call vdlgamma ( n , a , y )
call vdlgammai(n, a, inca, y, incy)
call vmdlgamma ( n , a , y , mode )
call vmdlgammai(n, a, inca, y, incy, mode)
Include Files
mkl_vml.f90
Input Parameters
Name |
Type |
Description |
|---|---|---|
n |
Specifies the number of elements to be calculated. |
|
a |
Fortran 77: DOUBLE PRECISION for vdlgamma , vmdlgammaFortran 90: REAL , INTENT(IN) for vslgamma , vmslgammaFortran 90: DOUBLE PRECISION , INTENT(IN) for vdlgamma , vmdlgamma |
Array that specifies the input vector a . |
inca , incy |
INTEGER, INTENT(IN) |
Specifies increments for the elements of a and y . |
mode |
INTEGER(KIND=8) , INTENT(IN) |
Overrides global VM mode setting for this function call. See vmlSetMode (Sets a new mode for VM functions according to the mode parameter and stores the previous VM mode to oldmode.) for possible values and their description. |
Output Parameters
Name |
Type |
Description |
|---|---|---|
y |
Fortran 77: DOUBLE PRECISION for vdlgamma , vmdlgammaFortran 90: REAL , INTENT(OUT) for vslgamma , vmslgammaFortran 90: DOUBLE PRECISION , INTENT(OUT) for vdlgamma , vmdlgamma |
Array that specifies the output vector y . |
Description
The v?LGamma function computes the natural logarithm of the absolute value of gamma function for elements of the input vector a and writes them to the output vector y . Precision overflow thresholds for the v?LGamma function are beyond the scope of this document. If the result does not meet the target precision, the function raises the OVERFLOW exception and sets the VM Error Status to VML_STATUS_OVERFLOW .
Special Values for Real Function v?LGamma(x)
Argument |
Result |
VM Error Status |
Exception |
|---|---|---|---|
+1 |
+0 |
||
+2 |
+0 |
||
+0 |
|
VML_STATUS_SING |
ZERODIVIDE |
-0 |
|
VML_STATUS_SING |
ZERODIVIDE |
negative integer |
|
VML_STATUS_SING |
ZERODIVIDE |
|
|
||
|
|
||
X > overflow |
|
VML_STATUS_OVERFLOW |
OVERFLOW |
QNAN |
QNAN |
||
SNAN |
QNAN |
INVALID |