www.gusucode.com > control 案例程序 matlab源码代码 > control/HankelSingularValuePlotWithNearUnstablePoleExample.m

    %% Hankel Singular-Value Plot with Near-Unstable Pole
% Compute the Hankel singular values of the system given by:
% 
% $$sys = \frac{{\left( {s + 0.5} \right)}}{{\left( {s + {{10}^{ - 6}}}
% \right)\left( {s + 2} \right)}}$$
% 
%% 
% Use the |Offset| option to force |hsvd| to exclude the pole at $s = {10^{
% - 6}}$ from the stable term of the stable/unstable decomposition.
sys = zpk(-.5,[-1e-6 -2],1); 
opts = hsvdOptions('Offset',.001); 
hsvd(sys,opts) 
%%
% The plot shows that one state is treated as unstable. |hsvd| computes the
% energy contributions of the stable states only.