9.170 LOG_GAMMA — Logarithm of the Gamma function

Description:

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

Standard:

Fortran 2008 and later

Class:

Elemental 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

See also:

Gamma function: GAMMA