%% Properties of uss Objects
% uss models, like all model objects, include properties that store dynamics and model metadata. View the properties of an uncertain state-space model.

p1 = ureal('p1',10,'Percentage',50);
p2 = ureal('p2',3,'PlusMinus',[-.5 1.2]);
p3 = ureal('p3',0);
A = [-p1 p2; 0 -p1];
B = [-p2; p2+p3];
C = [1 0; 1 1-p3];
D = [0; 0];
sys = ss(A,B,C,D);     % create uss model

get(sys)

%
% Most of the properties behave similarly to how they behave for ss model objects. The NominalValue property is itself an ss model object. You can therefore analyze the nominal value as you would any state-space model. For instance, compute the poles and step response of the nominal system.

pole(sys.NominalValue)

%

step(sys.NominalValue)

%
% As with the uncertain matrices (umat), the Uncertainty property is a structure containing the uncertain elements. You can use this property for direct access to the uncertain elements. For instance, check the Range of the uncertain element named p2 within sys.

sys.Uncertainty.p2.Range

%
% Change the uncertainty range of p2 within sys.

sys.Uncertainty.p2.Range = [2 4];

%
% This command changes only the range of the parameter called p2 in sys. It does not change the variable p2 in the MATLAB workspace.

p2.Range

% Copyright 2012 The MathWorks, Inc.