*DECK DLGAMS SUBROUTINE DLGAMS (X, DLGAM, SGNGAM) C***BEGIN PROLOGUE DLGAMS C***PURPOSE Compute the logarithm of the absolute value of the Gamma C function. C***LIBRARY SLATEC (FNLIB) C***CATEGORY C7A C***TYPE DOUBLE PRECISION (ALGAMS-S, DLGAMS-D) C***KEYWORDS ABSOLUTE VALUE OF THE LOGARITHM OF THE GAMMA FUNCTION, C FNLIB, SPECIAL FUNCTIONS C***AUTHOR Fullerton, W., (LANL) C***DESCRIPTION C C DLGAMS(X,DLGAM,SGNGAM) calculates the double precision natural C logarithm of the absolute value of the Gamma function for C double precision argument X and stores the result in double C precision argument DLGAM. C C***REFERENCES (NONE) C***ROUTINES CALLED DLNGAM C***REVISION HISTORY (YYMMDD) C 770701 DATE WRITTEN C 890531 Changed all specific intrinsics to generic. (WRB) C 890531 REVISION DATE from Version 3.2 C 891214 Prologue converted to Version 4.0 format. (BAB) C***END PROLOGUE DLGAMS DOUBLE PRECISION X, DLGAM, SGNGAM, DLNGAM C***FIRST EXECUTABLE STATEMENT DLGAMS DLGAM = DLNGAM(X) SGNGAM = 1.0D0 IF (X.GT.0.D0) RETURN C INT = MOD (-AINT(X), 2.0D0) + 0.1D0 IF (INT.EQ.0) SGNGAM = -1.0D0 C RETURN END