mat_rrot Subroutine

subroutine mat_rrot(n,dx,incx,dy,incy,c,s)

! ident_27="@(#)M_LA::mat_rrot(3f): Applies a plane rotation."

integer         :: n
doubleprecision :: dx(*)
integer         :: incx
doubleprecision :: dy(*)
integer         :: incy
doubleprecision :: c
doubleprecision :: s

doubleprecision :: dtemp
integer         :: i
integer         :: ix
integer         :: iy
!
   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
           dtemp = mat_flop(c*dx(ix) + s*dy(iy))
           dy(iy) = mat_flop(c*dy(iy) - s*dx(ix))
           dx(ix) = dtemp
           ix = ix + incx
           iy = iy + incy
      enddo
   endif
end subroutine mat_rrot