How i can get state space model from transfer function?

Hello, I tried alot with the code you can see in the picture. But it doesn`t work. I want to know if Matlab dosen`t support the function of tf2ss or I just have a mistake.

[code]

num = [0 0 0 5];

den = [1 6 5 0];

[A, B, C, D] = tf2ss(num,den)

[Error message]

Execution of script tf2ss as a function is not supported:

Error in tf2ss (line 6)

[A, B, C, D] = tf2ss(num,den)

Thank you for reading my question and if you know the answer, please leave a comment :)

Answer 1

[Star Strider]

Apparently you named a script ‘tf2ss’. This overshadows the tf2ss function.

The solution is to re-name the script to something that is meaningful and that does not overshadow MATLAB functions.

[상준 안]

Thank you for answering :)

Re-name the script to something means I cant use the text 'tf2ss' in Editor because of the name of function already exist, right? But I cant understand, how I can get the s.s.m from t.f without naming tf2ss in the script.

In youtube or help section in Matlab, there are some examples that use the 'tf2ss' in their script. I dont know what`s the difference between theirs and mine.

Maybe I cant understand the difference between the script and function.

Can you give me a simple example of renaming the the script 'tf2ss' to something.

Thank you for answering my question again :)

[Star Strider]

Name the script something like ‘tf2ss_demo’.

Then run the posted code from it, using the tf2ss function.

[상준 안]

\

To get S.S.M from T.F, I should use the tf2ss function. And I understand tf2ss in my script overshadows the tf2ss function. But how can I do without naming tf2ss in the script 😥

If I rename the tf2ss to something, Matlab cant recognize it.. I`m so sorry for not to understading your good advice.😓

[Star Strider]

I have apparently not made myself clear.

Please see the attached file. It is named ‘tf2ss_demo.m’ and it contains:

% tf2ss_demo.m

s = tf('s');

Htf = [(2*s+3); (s^2+2*s+1)] / (s^2+0.4*s+1)

b = Htf.Numerator
a = Htf.Denominator

[A,B,C,D] = tf2ss(cell2mat(b),cell2mat(a(1)))       % Signal Processing Toolbox

Hss = ss(Htf)                                       % Control System Toolbox

Import the file to your MATLAB user directory, then run it.

.

[상준 안]

Thank u so much :)

[Star Strider]

As always, my pleasure!