magpicard_residual Subroutine

  subroutine magpicard_residual(this, lev, dt, flags)
    class(pf_magpicard_t), intent(inout) :: this
    class(pf_level_t),    intent(inout) :: lev
    real(pfdp),           intent(in   ) :: dt
    integer, optional, intent(in   ) :: flags
    integer :: m

    do m = 1, lev%nnodes-1
       call lev%R(m)%axpy(-1.0_pfdp, lev%Q(m+1))
    end do

    lev%residual = lev%R(lev%nnodes-1)%norm()
  end subroutine magpicard_residual