Factorize transfer function

I need to divide my transfer function into 2 transfer functions in such way that S2 = S1' Actually I have product of S2*S1

s = tf('s')
Suu = -1.6/((s-4)*(s+4))
Sux = -0.8/((s+4)*(s-4)*(s^2 + 0.1*s + 1))
Sxx = 0.3*(s - 4.163)*(s + 4.163)/((s+4)*(s-4)*(s^2 - 0.1*s + 1)*(s^2 + 0.1*s + 1))
Sxu = Sux'
SxdSdx = Sxx - (Sxu*Sux)/Suu

How to determine Sxd and Sdx if Sxd = Sdx' ? Anybody can help me?

Answer 1

[Stefan Wehmeier]

Don't know how to do it using tf, but you can do

syms s
Suu = -1.6/((s-4)*(s+4))
Sux = -0.8/((s+4)*(s-4)*(s^2 + 0.1*s + 1))
Sxx = 0.3*(s - 4.163)*(s + 4.163)/((s+4)*(s-4)*(s^2 - 0.1*s + 1)*(s^2 + 0.1*s + 1))
Sxu = subs(Sux, s, -s)
SxdSdx = Sxx - (Sxu*Sux)/Suu
factor(SxdSdx)

or, to obtain a factorization of the numerator also,

feval(symengine, 'factor', SxdSdx, 'R_')