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getTestValue

Access test values for validating data function

Since R2023a

Description

t0 = getTestValue(vSys) returns the test time t0 used to validate the data function.

example

[t0,p0] = getTestValue(vSys) returns the test time t0 and parameter values p0 used to validate the data function of LPV models.

Examples

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For this example, the dataFcnMaglev.m data function describes the dynamics of a magnetic levitation system.

This model is not valid for height h = 0. Create an LPV model with a different value for the test height. For this model set t0 = 0 because the parameters do not depend explicitly on time.

h0 = 1;
sys = lpvss('h',@dataFcnMaglev,0,0,h0)
Continuous-time state-space LPV model with 1 outputs, 1 inputs, 2 states, and 1 parameters.

Get the test values lpvss used to validate dataFcnMaglev.m.

[t0,p0] = getTestValue(sys)
t0 = 0
p0 = 1

The function returns the same value that was used to validate the data function when you created the LPV object.

View the data function code.

type dataFcnMaglev.m
function [A,B,C,D,E,dx0,x0,u0,y0,Delays] = dataFcnMaglev(~,p)
% MAGLEV example:
% x = [h ; dh/dt]
% p=hbar (equilibrium height)
mb = 0.02; % kg
g = 9.81;
alpha = 2.4832e-5;
A = [0 1;2*g/p 0];
B = [0 ; -2*sqrt(g*alpha/mb)/p];
C = [1 0];  % h
D = 0;
E = [];
dx0 = [];
x0 = [p;0];
u0 = sqrt(mb*g/alpha)*p;  % ibar
y0 = p;                   % y = h = hbar + (h-hbar)
Delays = [];

Input Arguments

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LTV or LPV model, specified as an ltvss or lpvss object, respectively.

Output Arguments

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Test value of time, returned as a scalar. This is the value ltvss and lpvss uses to evaluate the data function.

Test values of parameters, returned as a vector of length equal to the number of parameters in the model. These are the values lpvss uses to evaluate the data function.

Version History

Introduced in R2023a