How to Plot Model Poles and Zeros Using the App

To create a pole-zero plot for parametric linear models in the System Identification app, select the Zeros and poles check box in the Model Views area. For general information about creating and working with plots, see Working with Plots.

To include or exclude a model on the plot, click the corresponding model icon in the System Identification app. Active models display a thick line inside the Model Board icon.

The following table summarizes the Zeros and Poles plot settings.

Zeros and Poles Plot Settings

ActionCommand
Display the confidence interval.
  • To display the dashed lines on either side of the nominal pole and zero values, select Options > Show confidence intervals. Select this option again to hide the confidence intervals.

  • To change the confidence value, select Options > Set % confidence level, and choose a value from the list.

  • To enter your own confidence level, select Options > Set confidence level > Other. Enter the value as a probability (between 0 and 1) or as the number of standard deviations of a Gaussian distribution.

Show real and imaginary axes.Select Style > Re/Im-axes. Select this option again to hide the axes.
Show the unit circle.Select Style > Unit circle. Select this option again to hide the unit circle. The unit circle is useful as a reference curve for discrete-time models.
(Multiple-output system only)
Select an input-output pair to view the poles and zeros corresponding to those channels.
Select the output by name in the Channel menu.

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