ADAS Subroutine a8gaml

       function a8gaml( xx )
c---------------------------------------------------------------------
c
c  ********************* fortran77 function a8gaml *******************
c
c  purpose: to evaluate log (gamma (xx)) for xx >0  - based on 
c           numerical recipes  
c
c  calling program:  a8gser.for , a8gcf
c
c  input:
c            (r*8)  xx      = parameter of gamma
c  output:
c            (r*8)  a8gaml = log gamma (xx)
c
c
c  routines: 
c             none
c
c  author:   Hugh Summers, University of Strathclyde ext.4196
c
c
c  version 1.1                             date:     25/06/99
c  modified: Hugh Summers
c		- first release
c
c-----------------------------------------------------------------------
      REAL*8              XX