Estimated state-space model of order `nx`

,
returned as an `idss`

model object.
The model represents:

$$\begin{array}{l}\dot{x}(t)=Ax(t)+Bu(t)+Ke(t)\\ y(t)=Cx(t)+Du(t)+e(t)\end{array}$$

*A*, *B*, *C*, *D*,
and *K* are state-space matrices. *u*(*t*)
is the input, *y*(*t*) is the output, *e*(*t*)
is the disturbance and *x*(*t*)
is the vector of `nx`

states.

All the entries of *A*, *B*, *C*,
and *K* are free estimable parameters by default. *D* is
fixed to zero by default, meaning that there is no feedthrough, except
for static systems (`nx=0`

).

Initial states computed during estimation, returned as a scalar.
If `data`

contains multiple experiments, then `x0`

is a matrix with each column corresponding
to an experiment.

This value is also stored in the `Parameters`

field
of the model's `Report`

property.