psran.f

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!          defined in QGSJETII-03 but not in II-04
       real*8 function psran(seed)
       implicit none
       real*8 seed
       real*8 u
       call  rndc(u)
       psran = u
       end
!=======================================================================
!            GAMFUN is defined in qgsjetII-03 but not in II-04.
      DOUBLE PRECISION FUNCTION gamfun(Y)
! Gamma function : See Abramowitz, page 257, form. 6.4.40
!-----------------------------------------------------------------------
      IMPLICIT DOUBLE PRECISION(a-h,o-z)
      double precision
     +     y,r,s,t,afspl,x,
     +     coef(10),pi,zerod,halfd,oned,twod,tend
      SAVE
!
      DATA coef/8.3333333333333334d-02,-2.7777777777777778d-03,
     .          7.9365079365079365d-04,-5.9523809523809524d-04,
     .          8.4175084175084175d-04,-1.9175269175269175d-03,
     .          6.4102564102564103d-03,-2.9550653594771242d-02,
     .          0.1796443723688306    ,-0.6962161084529506    /
      DATA pi/  3.141592653589793d0/
      DATA zerod/0.d0/,halfd/0.5d0/,oned/1.d0/,twod/2.d0/,tend/10.d0/
!
      x=y
      afspl=oned
      n=int(tend-y)
      DO 10 i=0,n
        afspl=afspl*x
        x=x+oned
10    CONTINUE
      r=(x-halfd)* log(x)-x+halfd* log(twod*pi)
      s=x
      t=zerod
      DO 20 i=1,10
        t=t+coef(i)/s
        s=s*x**2
20    CONTINUE
      gamfun = exp(r+t)/afspl
      END