00001 *DECK ALGAMS 00002 SUBROUTINE ALGAMS (X, ALGAM, SGNGAM) 00003 C***BEGIN PROLOGUE ALGAMS 00004 C***PURPOSE Compute the logarithm of the absolute value of the Gamma 00005 C function. 00006 C***LIBRARY SLATEC (FNLIB) 00007 C***CATEGORY C7A 00008 C***TYPE SINGLE PRECISION (ALGAMS-S, DLGAMS-D) 00009 C***KEYWORDS ABSOLUTE VALUE OF THE LOGARITHM OF THE GAMMA FUNCTION, 00010 C FNLIB, SPECIAL FUNCTIONS 00011 C***AUTHOR Fullerton, W., (LANL) 00012 C***DESCRIPTION 00013 C 00014 C Evaluates the logarithm of the absolute value of the gamma 00015 C function. 00016 C X - input argument 00017 C ALGAM - result 00018 C SGNGAM - is set to the sign of GAMMA(X) and will 00019 C be returned at +1.0 or -1.0. 00020 C 00021 C***REFERENCES (NONE) 00022 C***ROUTINES CALLED ALNGAM 00023 C***REVISION HISTORY (YYMMDD) 00024 C 770701 DATE WRITTEN 00025 C 890531 Changed all specific intrinsics to generic. (WRB) 00026 C 890531 REVISION DATE from Version 3.2 00027 C 891214 Prologue converted to Version 4.0 format. (BAB) 00028 C***END PROLOGUE ALGAMS 00029 C***FIRST EXECUTABLE STATEMENT ALGAMS 00030 ALGAM = ALNGAM(X) 00031 SGNGAM = 1.0 00032 IF (X.GT.0.0) RETURN 00033 C 00034 INT = MOD (-AINT(X), 2.0) + 0.1 00035 IF (INT.EQ.0) SGNGAM = -1.0 00036 C 00037 RETURN 00038 END
1.7.1
