      subroutine wwdiv(ar,ai,br,bi,cr,ci,ierr)
c!but
c
c     This subroutine wwdiv computes c=a/b where a and b are complex numbers
c
c!Calling sequence
c
c     subroutine wdivt(ar,ai,br,bi,cr,ci,ierr)
c
c     ar, ai: double precision, a real and complex parts.
c
c     br, bi: double precision, b real and complex parts.
c
c     cr, ci: double precision, c real and complex parts.
c
c!author
c
c     cleve moler.
c
c!
      double precision ar,ai,br,bi,cr,ci
c     c = a/b
      double precision s,d,ars,ais,brs,bis
c
      ierr=0
      s = abs(br) + abs(bi)
      if (s .eq. 0.0d+0) then
         ierr=1
         return
      endif
      ars = ar/s
      ais = ai/s
      brs = br/s
      bis = bi/s
      d = brs**2 + bis**2
      cr = (ars*brs + ais*bis)/d
      ci = (ais*brs - ars*bis)/d
      return
      end
