hijing/src/pyhigamm.f

0001
0002 C*********************************************************************
0003
0004       FUNCTION PYHIGAMM(X)
0005
0006 C...Gives ordinary Gamma function Gamma(x) for positive, real arguments;
0007 C...see M. Abramowitz, I. A. Stegun: Handbook of Mathematical Functions
0008 C...(Dover, 1965) 6.1.36.
0009       DIMENSION B(8)
0010       DATA B/-0.577191652,0.988205891,-0.897056937,0.918206857,
0011      &-0.756704078,0.482199394,-0.193527818,0.035868343/
0012
0013       NX=INT(X)
0014       DX=X-NX
0015
0016       PYHIGAMM=1.
0017       DO 100 I=1,8
0018   100 PYHIGAMM=PYHIGAMM+B(I)*DX**I
0019       IF(X.LT.1.) THEN
0020         PYHIGAMM=PYHIGAMM/X
0021       ELSE
0022         DO 110 IX=1,NX-1
0023   110   PYHIGAMM=(X-IX)*PYHIGAMM
0024       ENDIF
0025
0026       RETURN
0027       END