Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 7/13/2023
Public

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Document Table of Contents

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

INTEGER, INTENT(IN)

Specifies the number of elements to be calculated.

a

DOUBLE PRECISION for vdlgamma, vmdlgamma

REAL, INTENT(IN) for vslgamma, vmslgamma

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 for possible values and their description.

Output Parameters

Name

Type

Description

y

DOUBLE PRECISION for vdlgamma, vmdlgamma

REAL, INTENT(OUT) for vslgamma, vmslgamma

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