complex function cgamr (z)
  c july 1977 edition.  w. fullerton, c3, los alamos scientific lab.
  c this version is an inaccurate preliminary one.  eventually this
  c routine should be a fundamental routine with no dependence on cgamma.
  c
        complex z, cexp, clngam
        external  clngam
  c
        cgamr = (0.0, 0.0)
        x = real (z)
        if (x.le.0.0 .and. aint(x).eq.x .and. 0.0.eq.aimag(z)) return
  c
        call entsrc (irold, 1)
        cgamr = clngam(z)
        call erroff
        call entsrc (ir, irold)
        cgamr = cexp (-cgamr)
  c
        return
        end