To create a frequency-response plot for linear models in the System Identification app, select the Frequency resp 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 Frequency Function plot settings.
Frequency Function Plot Settings
Display the confidence interval.
Change the frequency values for computing the noise spectrum.
The default frequency vector is 128 linearly distributed values, greater than zero and less than or equal to the Nyquist frequency.
Select Options > Frequency range and specify a new frequency vector in units of rad/s.
Enter the frequency vector using any one of following methods:
To restore the default frequency vector, enter
|Change frequency units between hertz and radians per second.||Select Style > Frequency (Hz) or Style > Frequency (rad/s).|
|Change frequency scale between linear and logarithmic.||Select Style > Linear frequency scale or Style > Log frequency scale.|
|Change amplitude scale between linear and logarithmic.||Select Style > Linear amplitude scale or Style > Log amplitude scale.|
(Multiple-output system only)
You cannot view cross spectra between different outputs.
|Select the output by name in the Channel menu.|