LOG_GAMMA(X) (Fortran 2008)

Purpose

Logarithm of the absolute value of the GAMMA function.
Natural logarithm of GAMMA(X)

Class

Elemental function

Argument type and attributes

X
must be of type real. Its value must be greater than 0.

Result type and attributes

Same as X.

Result value

The result value approximates the natural logarithm of the absolute value of the GAMMA function of X, namely LOG(ABS(GAMMA(X))).

Examples

LOG_GAMMA(1.0) has the value 0.0, approximately.

Specific Name Argument Type Result Type Pass As Arg?
LGAMMA default real default real no
LGAMMA double precision real double precision real no
ALGAMA  1   2  default real default real yes
DLGAMA  1   3  double precision real double precision real yes
QLGAMA  1   4  REAL(16) REAL(16) yes
Notes:
  •  1  IBM extension
  • X must satisfy the inequality:
    •  2  0 < X ≤ 4.0850E36
    •  3  2.3561D-304 ≤ X ≤ 21014
    •  4  2.3561Q-304 ≤ X ≤ 21014

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