%% Norm of MIMO System
% Compute the H_{\infty} norm of the following 2-input, 2-output dynamic system and the frequency at which the peak singular value occurs.
% G\left(s\right)=\left\lbrack \begin{array}{cc}
% 0 & \frac{3s}{s^2 +s+10}\\
% \frac{s+1}{s+5} & \frac{2}{s+6}
% \end{array}\right\rbrack \ldotp

G = [0 tf([3 0],[1 1 10]);tf([1 1],[1 5]),tf(2,[1 6])];
[ninf,fpeak] = hinfnorm(G)

%
% The H_{\infty} norm of a MIMO system is its maximum singular value. Plot the singular values of G and compare the result from hinfnorm.

sigma(G),grid

% The values ninf and fpeak are consistent with the singular value plot, which displays the values in dB.
% Copyright 2012 The MathWorks, Inc.