% Script e8 Series/parallel multi block system
  clear % removes all variables from the workspace
  G1 = tf([2 3],[5 2 2])  
  G2 = tf([5 10],[1 8.5 4])
  G3 = tf([2 6],[1 1 8])
  pause
  G4 = tf([1 4],conv([1 1],[1 4 1]))
  pause
  T = G4*(G3 + G2*G1) % transfer function of the entire system
%  T = series(G4,parallel(G3, series(G2,G1))) % Alternative computation
   pause
  Tzpk = zpk(T) % Entire system in zpk form
  pause
  Tpoles = pole(T), Tzeros = zero(T)  % get the poles and zeros of T
  pause
  TgainDC = dcgain(T), step(T) % compute the DC gain and the step response