Routh stability criteria function

With this function you can evaluate numerically the Routh stability test for LTI systems, even special cases.

Routh - Hurwitz stability criteria M-Function for linear - time invariant - continuos systems.

The Routh - Hurwitz stability criteria is a common tool for LTI systems control desing, this function evaluates (numerically) the criteria, prompting for user input if any of the two special cases are found: first element of row = 0 or all row = 0.

In the first case prompt will ask for a small value in order to continue, its sugested input values equal or under 0.001. For de second especial case the prompt will only advise you that an special case is found so you can know that an auxiliar polinomial was constructed and its firts derivate was obtained.

General use: [STABLE] = Routh(SYS)

STABLE = 1 if the system is stable, 0 if doesnt

SYS = System to test in "tf" type

Alternative use:

[STABLE] = Routh(DEN)

DEN = polinomial coeficients of the TF denominator.

[STABLE] = Routh(A)

A = Systema Matrix, for time space representation.

The function can also return the criteria table:

[STABLE,TABLE] = Routh(SYS or DEN or A)

Also, discrete time version avilable .

Thanks for using and comments allways wellcome.