# Various realizations of state-space.

function ControllableForm(S::StateSpace)::StateSpace
    # Todo

end

function ObservableForm(S::StateSpace)::StateSpace
    # Todo

end

function KalmanDecomposition(S::StateSpace)::StateSpace
    # Todo
end

function ModalForm(S::StateSpace)::StateSpace
    # Todo
end

function BalancedForm(S::StateSpace)::StateSpace # Hankel form.
    # Todo
end

function MinimalRealization(S::StateSpace)::StateSpace
    # Todo
end

function SlowFastDecomposition(S::StateSpace)::StateSpace
    # Todo
end

function StableUnstableDecomposition(S::StateSpace)::StateSpace
    # Todo
end
