complex(kind(1.d0)) function zgamma (z)
      implicit none
c july 1977 edition.  w. fullerton, c3, los alamos scientific lab.
c a preliminary version that is portable, but not accurate enough.
      complex(kind(1.d0)) z, zlngam
      external zlngam
c
      zgamma = exp (zlngam(z))
c
      return
      end