MATLAB Answers


Undefined function or variable 'A'.

Asked by Abhibrata Adhikary on 2 Sep 2016
Latest activity Answered by PRUDHVI RAJU on 2 Sep 2016
I am trying to solve this question A = [-2 -4 -6 1 0 0 0 1 0]; B = [1 0 0]; C = [0 0 1]; D = 0; but when i am giving the command sys = ss(A,B,C,D), its showing the error "Undefined function or variable 'A'.".
Can anyone please help me how to solve the problem? I am using trial version of MATLAB on my system.

  1 Comment

Which version of Matlab you are using? In version 2015b 'ss' command is used to create a state-space model, and error I am getting is:
Error using ss (line 330)
The values of the "a" and "e" properties must be square matrices.

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1 Answer

Answer by PRUDHVI RAJU on 2 Sep 2016

sys = ss(a,b,c,d) creates a state-space model object representing the continuous-time state-space model
For a model with Nx states, Ny outputs, and Nu inputs:
a is an Nx-by-Nx real- or complex-valued matrix.
b is an Nx-by-Nu real- or complex-valued matrix.
c is an Ny-by-Nx real- or complex-valued matrix.
d is an Ny-by-Nu real- or complex-valued matrix.
To set D = 0 , set d to the scalar 0 (zero), regardless of the dimension.


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