%%%%%%%%%%%%%%%%%% Example 2.1 %%%%%%%%%%%%%%%%%%%   Discrete-Time Control Problems using        %%       MATLAB and the Control System Toolbox   %%   by J.H. Chow, D.K. Frederick, & N.W. Chbat  %%         Brooks/Cole Publishing Company        %%                September 2002                 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   ---- Build G(z) as TF object ----%cleardisp('Example 2.1')numG = [0.1 0.03 -0.07]           % enter transfer function numeratordenG = [1 -2.7 2.42 -0.72]        % ...and denominator polynomials%-- Create G(z) as a discrete-time TF object with unspecified sampling periodG = tf(numG,denG,-1)get(G)                            % Show properties of the TF objectdisp('******>'), pause[nn,dd] = tfdata(G,'v')[zz,pp,kk] = zpkdata(G,'v')       % Extract num & den from the TF objectucircle, hold on                  % show unit circle in z-planepzmap(G), hold off                % draw pole-zero plotset_xo_size                       % make larger X's and O'stitle('Example 2.1')%%%%%%%%%%