Routh Pade Approximation

The code derives the reduced order approximant of a desired degree for a given transfer function.

The method used is the Routh-Pade Approximation.

Computes the r-th order Routh-Pade Approximation of a given n-th order stable transfer function G, with 1<=r<=n. The denominator of the reduced model is computed using the reduced routh/gamma table. The numerator on the other hand is computed by moment matching.

Example
G=tf([1 2],[1 3 4 5])
r=2;
R=Routh_Pade(G,r)

gives the output

Transfer function:
0.5714 s + 1.143
---------------------
s^2 + 2.286 s + 2.857