I want to use some data to estimate a state space model of a dynamical system. I know I can use ssest command. Yet when I am using it, it returns model with very extrange C matrix very far from 1 or [1 0] (like C=15.6438 or C=[18.72 7.32], etc.). Yet I know from its characteristic that the dynamical system I want to identify has a trivial C matrix C=1 or C=[1 0]. Is there a way to designate the C matrix to be 1 or [1 0] when using ssest command to estimate the dynamical system? Or are there methods other than ssest to estimate the state space model of a dynamical system?