ss2tf - conversion from state-space to transfer function
Called with three outputs [Ds,NUM,chi]=ss2tf(sl) returns the numerator polynomial matrix NUM, the characteristic polynomial chi and the polynomial part Ds separately i.e.:
h=NUM/chi + Ds
Method:
One uses the characteristic polynomial and det(A+Eij)=det(A)+C(i,j) where C is the adjugate matrix of A.
With rmax or "b" argument uses a block diagonalization of sl.A matrix and applies "Leverrier" algorithm on blocks. If given, rmax controls the conditionning (see bdiag).
s=poly(0,'s'); h=[1,1/s;1/(s^2+1),s/(s^2-2)] sl=tf2ss(h); h=clean(ss2tf(sl)) [Ds,NUM,chi]=ss2tf(sl)