Using `feedback` with feedback gains argument

In the feedback.m documentation (both help and online documentation), I'm only seeing examples where two state space / transfer function models must be provided.

For example -- in documentation, I see feedback(sys1, sys2, ...). However, I seem to be able to instead provide feedback(sys1, k) where k is a feedback gain (vector for SISO systems).

I guess my question is - is feedback(sys, k) doing what I think it's doing?

[Mathieu NOE]

probably yes

the two examples below gives the same closed loop tf

G = tf([2 5 1],[1 2 3],'inputname',"torque",'outputname',"velocity");
C = tf([1],[1]); % unitary gain

% Use feedback to create the negative feedback loop using G and C.

sys = feedback(G,C,-1)

% equivalent to : 

sys = feedback(G,1) % ! assumed neg feedback here 

Answer 1

[Ameer Hamza]

A scalar 'k' is also a static gain transfer function. So you are correct; in your case, 'k' is the same as negative feedback gain.