8.155 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

© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-4.9.3/gfortran/LOG_005fGAMMA.html