Fortran Wiki
gamma

Description

gamma(x) computes Gamma (Γ) of x. For positive, integer values of x the Gamma function simplifies to the factorial function Γ(x)=(x1)!.

Γ(x)= 0 t x1e tdt\Gamma(x) = \int_0^\infty t^{x-1}{\mathrm{e}}^{-t}\,{\mathrm{d}}t

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

See also

Logarithm of the Gamma function: log_gamma

category: intrinsics