[u/mrichter/AliRoot.git] / HIJING / hipyset1_35 / pygamm_hijing.F

* $Id$
    
C*********************************************************************  
    
      FUNCTION PYGAMM_HIJING(X)    
    
C...Gives ordinary Gamma function Gamma(x) for positive, real arguments;    
C...see M. Abramowitz, I. A. Stegun: Handbook of Mathematical Functions 
C...(Dover, 1965) 6.1.36.   
      DIMENSION B(8)    
      DATA B/-0.577191652,0.988205891,-0.897056937,0.918206857, 
     &-0.756704078,0.482199394,-0.193527818,0.035868343/    
    
      NX=INT(X) 
      DX=X-NX   
    
      PYGAMM_HIJING=1. 
      DO 100 I=1,8  
  100 PYGAMM_HIJING=PYGAMM_HIJING+B(I)*DX**I  
      IF(X.LT.1.) THEN  
        PYGAMM_HIJING=PYGAMM_HIJING/X 
      ELSE  
        DO 110 IX=1,NX-1    
  110   PYGAMM_HIJING=(X-IX)*PYGAMM_HIJING    
      ENDIF 
    
      RETURN    
      END
Commit	Line	Data
e74335a4	1	* $Id$
	2
	3	C*********************************************************************
	4
	5	FUNCTION PYGAMM_HIJING(X)
	6
	7	C...Gives ordinary Gamma function Gamma(x) for positive, real arguments;
	8	C...see M. Abramowitz, I. A. Stegun: Handbook of Mathematical Functions
	9	C...(Dover, 1965) 6.1.36.
	10	DIMENSION B(8)
	11	DATA B/-0.577191652,0.988205891,-0.897056937,0.918206857,
	12	&-0.756704078,0.482199394,-0.193527818,0.035868343/
	13
	14	NX=INT(X)
	15	DX=X-NX
	16
	17	PYGAMM_HIJING=1.
	18	DO 100 I=1,8
	19	100 PYGAMM_HIJING=PYGAMM_HIJING+B(I)DX*I
	20	IF(X.LT.1.) THEN
	21	PYGAMM_HIJING=PYGAMM_HIJING/X
	22	ELSE
	23	DO 110 IX=1,NX-1
	24	110 PYGAMM_HIJING=(X-IX)*PYGAMM_HIJING
	25	ENDIF
	26
	27	RETURN
	28	END