LOG_GAMMA — Logarithm of the Gamma function

Description

LOG_GAMMA(X) computes the natural logarithm of the absolute value of the Gamma (\Gamma) function.

Syntax

X = LOG_GAMMA(X)

Arguments

X Shall be of type REAL and neither zero nor a negative integer.

Return value

The return value is of type REAL of the same kind as X.

Example



program test_log_gamma

  real :: x = 1.0

  x = lgamma(x) ! returns 0.0

end program test_log_gamma

Specific names

Name Argument Return type Standard
LGAMMA(X) REAL(4) X REAL(4) GNU Extension
ALGAMA(X) REAL(4) X REAL(4) GNU Extension
DLGAMA(X) REAL(8) X REAL(8) GNU Extension

Standard

Fortran 2008 and later

Class

Elemental function

Name	Argument	Return type	Standard
`LGAMMA(X)`	`REAL(4) X`	`REAL(4)`	GNU Extension
`ALGAMA(X)`	`REAL(4) X`	`REAL(4)`	GNU Extension
`DLGAMA(X)`	`REAL(8) X`	`REAL(8)`	GNU Extension