set the value of the variable in Transfer Function????

Question

Stephan 2012-11-25

Hi guys,

I have some problems with my transfer function. My Transfer Function is a 2x2 matrix. The variable is 's'.

Looks like this:

Gtf = [s/s+1 s+2; s-3/s+4 s+1]

Now I would like to get Gtf(5) (set s=5) to perform the Singular Value Decomposition with that matrix. I would like MATLAB to show me the following:

Gtf = [5/6 7; 2/9 6]

How can i get there?

So my problem is: how can I set the variable of the transfer function matrix to a value?

Thanks in advance

Answer 1

Jonathan Epperl 2012-11-25

That is what the functions freqresp and evalfr are for. In your case:

evalfr(Gtf,5)

However, I hope you just forgot the () in your example, i.e. in your real code it is s/(s+1) and not s/s+1 etc.

Stephan 2012-11-28

Thank you very much!