# I need to input a matrix of size 2x2 which is something like this A= [ 1 - 1.8629z-1 + 0.8669z-2 , 0 ; 0 , 1 -1.8695z-1 + 0.8737z- 2 ] which is a 2x2 Matrix

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Nithyaananth on 29 Mar 2024
Commented: Nithyaananth on 29 Mar 2024
I need to input this into my Code.
Star Strider on 29 Mar 2024
Does it have an associated denominator polynomial in z?
Nithyaananth on 29 Mar 2024
Basically, the first matrix is the discretized transfer functions for a 2 input and 2 output system. Next to get A(z^-1) = [(den11)*(den12) 0; 0 (den21)*(den22)] this has to be done.

John D'Errico on 29 Mar 2024
Edited: John D'Errico on 29 Mar 2024
So do it. What is the problem? If z is known, then just type it in, pretty much as written.
Do you know how to raise a number to a power? Actually, z^-1 is just 1/z, a far simpler way to write the power. For example:
z = 1.5;
A = [1-1.8629/z + 0.8669/z^2, 0; ...
0, 1 - 1.8695/z + 0.8737/z^2]
A = 2×2
0.1434 0 0 0.1420
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If all of this seems foreign to you, then you STRONGLY need to start with the basics of MATLAB. Do the MATLAB Onramp. And there are other basic MATLAB tutorials to be found.
Nithyaananth on 29 Mar 2024
Z is not known here,
Basically, the first matrix is the discretized transfer functions for a 2 input and 2 output system. Next to get A(z^-1) = [(den11)*(den12) 0; 0 (den21)*(den22)] this has to be done.

Torsten on 29 Mar 2024
Define A as a function of z:
A = @(z)[1-1.8629*z,0;0,1-1.8695*z+0.8737*z^2];
A(2)
ans = 2x2
-2.7258 0 0 0.7558
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or as a symbolic matrix
syms z A(z)
A(z) = [1-1.8629*z,0;0,1-1.8695*z+0.8737*z^2];
A(2)
ans =