GNU Octave  4.0.0
A high-level interpreted language, primarily intended for numerical computations, mostly compatible with Matlab
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Properties Friends Macros Pages
dlgams.f
Go to the documentation of this file.
1 *DECK DLGAMS
2  SUBROUTINE dlgams (X, DLGAM, SGNGAM)
3 C***BEGIN PROLOGUE DLGAMS
4 C***PURPOSE Compute the logarithm of the absolute value of the Gamma
5 C function.
6 C***LIBRARY SLATEC (FNLIB)
7 C***CATEGORY C7A
8 C***TYPE DOUBLE PRECISION (ALGAMS-S, DLGAMS-D)
9 C***KEYWORDS ABSOLUTE VALUE OF THE LOGARITHM OF THE GAMMA FUNCTION,
10 C FNLIB, SPECIAL FUNCTIONS
11 C***AUTHOR Fullerton, W., (LANL)
12 C***DESCRIPTION
13 C
14 C DLGAMS(X,DLGAM,SGNGAM) calculates the double precision natural
15 C logarithm of the absolute value of the Gamma function for
16 C double precision argument X and stores the result in double
17 C precision argument DLGAM.
18 C
19 C***REFERENCES (NONE)
20 C***ROUTINES CALLED DLNGAM
21 C***REVISION HISTORY (YYMMDD)
22 C 770701 DATE WRITTEN
23 C 890531 Changed all specific intrinsics to generic. (WRB)
24 C 890531 REVISION DATE from Version 3.2
25 C 891214 Prologue converted to Version 4.0 format. (BAB)
26 C***END PROLOGUE DLGAMS
27  DOUBLE PRECISION X, DLGAM, SGNGAM, DLNGAM
28 C***FIRST EXECUTABLE STATEMENT DLGAMS
29  dlgam = dlngam(x)
30  sgngam = 1.0d0
31  IF (x.GT.0.d0) RETURN
32 C
33  int = mod(-aint(x), 2.0d0) + 0.1d0
34  IF (int.EQ.0) sgngam = -1.0d0
35 C
36  RETURN
37  END
subroutine dlgams(X, DLGAM, SGNGAM)
Definition: dlgams.f:2
octave_int< T > mod(const octave_int< T > &x, const octave_int< T > &y)
Definition: oct-inttypes.h:959