Compute and test residuals

`resid(`

computes
the 1-step-ahead prediction errors (residuals) for an identified model, `Data`

,`sys`

)`sys`

,
and plots residual-input dynamics as one of the following, depending
on the data in`Data`

:

For time-domain data,

`resid`

plots the auto-=correlation of the residuals and the cross-correlation of the residuals with the input signals. The correlations are generated for lags -25 to 25. To specify a different maximum lag value, use`residOptions`

. The 99% confidence region marking statistically insignificant correlations displays as a shaded region around the X-axis.For frequency-domain data,

`resid`

plots a bode plot of the frequency response from the input signals to the residuals. The 99% confidence region marking statistically insignificant response is shown as a region around the X-axis.

To change display options, right-click the plot to access the context menu. For more details about the menu, see Tips.

`resid(`

computes
and plots the residual of multiple identified models `Data`

,sys1,...,sysn)`sys1`

,...,`sysn`

.

[1] Ljung, L. *System Identification: Theory for
the User*. Upper Saddle River, NJ: Prentice-Hall PTR, 1999,
Section 16.6.

`compare`

| `predict`

| `residOptions`

| `sim`

| `simsd`

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