%% Create Uncertain LTI Dynamics
% You can create a 1-by-1 (scalar) positive-real uncertain linear dynamics element, whose frequency response always has real part greater than -0.5. Set the SampleStateDimension property to 5. Plot a Nyquist plot of 30 instances of the element.

g = ultidyn('g',[1 1],'Type','Positivereal','Bound',-0.5); 
g.SampleStateDimension = 5;

%

nyquist(usample(g,30)) 
xlim([-2 10]) 
ylim([-6 6]);

% Copyright 2015 The MathWorks, Inc.