Undefined function or variable 'A'.

Hi,

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.

Thanks

[Pawel Ladosz]

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.

Answer 1

[PRUDHVI RAJU]

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.