State

space model. A mathematical relationship of a system in time using state variables, inputs, outputs, and constants; The state-space model is composed of n state variables (x sub 1 , x sub 2 , ..., x sub n), m input variables (u sub 1 , u sub 2 , ..., u sub m), k output variables (y sub 1 , y sub 2 , ..., y sub k), and four constants a, b, c, and d. Alternatively, a state-space model can be expressed with matrices. Compare: continuous-time equation, difference equation, differential equation, discrete-time equation, Laplace transform, Z transform;