mat_wdotui Function

doubleprecision function mat_wdotui(n,xr,xi,incx,yr,yi,incy)
integer         :: n
doubleprecision :: xr(*)
doubleprecision :: xi(*)
integer         :: incx
doubleprecision :: yr(*)
doubleprecision :: yi(*)
integer         :: incy
doubleprecision :: s
integer         :: ix
integer         :: iy
integer         :: i
   s = 0.0d0
   if (n .gt. 0) then
      ix = 1
      iy = 1
      if (incx.lt.0) ix = (-n+1)*incx + 1
      if (incy.lt.0) iy = (-n+1)*incy + 1
      do i = 1, n
         s = s + xr(ix)*yi(iy) + xi(ix)*yr(iy)
         if (s .ne. 0.0d0) s = mat_flop(s)
         ix = ix + incx
         iy = iy + incy
      enddo
   endif
   mat_wdotui = s
end function mat_wdotui