User`s guide

1 Data Processing
Commands for Plotting Data (Continued)
Command
Description
Exampl e
ffplot
For frequency-response
data only. Show s the
magnitude and phase of
the f requency respons e on
a linear f requency scale
(hertz).
To plot
idfrd data:
ffplot(idfrd_data)
plot
The type of plot corresponds
to the type of d ata.
For example, plotting
time-domain d ata generates
a time plot, and plotting
frequency-response
data generates a
frequency-response plot.
When plotting time- or
frequency-domain inputs
and outputs, the top axes
show the output and the
bottom axes show the input.
To plot
iddata or id frd
data:
plot(data)
Note For idfrd data, this
command is equivalent to
ffplot(data).
All plot commands display the data in the standard MATLAB Figure window.
For more information about working with the Figure window, see the
MATLAB Graphics documentation.
To plot portions of the data, you can subreference speci fic samples (see
“Subreferencing iddata Objects” on page 1-55 and “Subreferencing idfrd
Objects” on page 1-70. For example:
plot(data(1:300))
For time-domain data, to plot only the input data as a function of time, use
the following syntax:
plot(data(:,[],:)
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