Singular values plot of a transfer function

Question

I have a small question!

If I have a transfer function matrix $G(s) $ and want to plot all singular values, like a bode plot, except for the phase part. Can I just find the frequency gain and then use SVD in Octave/MATLAB to plot every dot ?

For example $G (0) $ will give me the low frequency gain. In this case it will be a matrix of real numbers. I use $svd (G(0)) = U S V^T$ and get the singular values matrix $S $. Store from $S $ into a vector and then use the next frequency $s $ for the transfer function.

Or do I need to use $j\omega $ insted of $s $?

Is that correct?

Answer 1

The answer is that I need to use $s$ as $j\omega $ and I use the MATLAB/Octave Command

$$ \bar{\sigma} = norm(G(j\omega), 2) $$ To get the maximum singular value.