User`s guide

Using Frequency-Response Plots to Validate Models
where sd is the number of standard deviations of a Gaussian distributio n. For
example, a confidence value of 99% for the nominal model curve corresponds
to 2.58 stand a rd d e v ia t ions.
To display a filled confidence region, use the following syntax:
command(model, 'sd' ,sd,'fill')
ThefollowingtablesummarizescommandsthatgenerateBodeandNyquist
plots for linear models. For detailed info rm ation about each command and
how to s pecify the frequency values for computing the response, see the
corresponding reference page.
Command
Description
Exampl e
bode
Plots the m agnitude
and phase of the
frequency response on
a logarithmic frequency
scale.
To create the bode plot
of the model
mod,use
the following command:
bode(mod)
ffplot
Plots the m agnitude
and phase of the
frequency response
on a linear frequency
scale (hertz).
To create the bode plot
of the model
mod,use
the following command:
ffplot(mod)
nyquist
Plots the imaginary
versus real part of the
transfer function.
Note Does not support
time-series models.
To plot the frequency
response of the m odel
mod,usethefollowing
command:
nyquist(mod)
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