How to calculate state vectors in the state space equations....?

I have set of input and set of output. with that i generated state space equations using system identification tool. now i want to test my state state equation with given set of inputs. but i am facing difficulty that how i have to give state vectors in the state space model to check my output. can anyone help me to calculate or find the state vectors in the state space model.

[John D'Errico]

This is a pretty vague question. Such a question is quite difficult to answer, since nobody knows exactly what problems you are having in terms of MATLAB. If you have no MATLAB problems, then this question is off-topic on MATLAB Answers. So show what you are doing. Then ask a specific question in regards to the code.