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/GNU Fortran 7

9.118 GAMMA — Gamma function

Description:

GAMMA(X) computes Gamma (\Gamma) of X. For positive, integer values of X the Gamma function simplifies to the factorial function \Gamma(x)=(x-1)!.

Standard:

Fortran 2008 and later

Class:

Elemental function

Syntax:

X = 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_gamma
  real :: x = 1.0
  x = gamma(x) ! returns 1.0
end program test_gamma
Specific names:
Name Argument Return type Standard
GAMMA(X) REAL(4) X REAL(4) GNU Extension
DGAMMA(X) REAL(8) X REAL(8) GNU Extension
See also:

Logarithm of the Gamma function: LOG_GAMMA

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Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gfortran/GAMMA.html