www.gusucode.com > robust 案例源码程序 matlab代码 > robust/NormofMIMOSystemExample.m

    %% 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. 
% 
%%
% 
% $$G\left( s \right) = \left[ {\begin{array}{*{20}{c}}
% 0&{\displaystyle \frac{{3s}}{{{s^2} + s + 10}}}\\[2.0ex]
% {\displaystyle \frac{{s + 1}}{{s + 5}}}&{\displaystyle \frac{2}{{s + 6}}}
% \end{array}} \right].$$
% 
%%  

% Copyright 2015 The MathWorks, Inc.

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.