User`s guide

Analyzing Data Quality Using Plots
When data.intersample = 'zoh', the input is piece-wise constant between
sampling points on the plot. For more information about properties, see the
iddata reference p age.
You can generate plots of the input data in the tim e dom a in using:
plot(data.sa,data.u)
To plot frequency-domain data, you can use the following syntax:
semilogx(data.fr,abs(data.u))
In this case, sa is an a b breviation of the iddata property SamplingInstants.
Similarly,
fr is an abbreviation of Frequency. u is the input signal.
Note The frequencies are linearly spaced on the plot.
When you specify to plot a multiv a riable iddata object, each input-output
combina tion is dis pl ayed one at a time in the same MATLAB Figu r e window.
You must press Enter to update the Figure window and view the next
channel combination. To cancel the plotting operatio n, press Ctrl+C.
Tip To plot specific input and output channels, use p lot(data(:,ky,ku)),
where
ky and ku are specific output and input channel indexes or names. For
more information about subre fere n cin g channels, see “Subreferencing Data
Channels” on page 1-56.
To plot several i ddata sets d1,...,dN,useplot(d1,...,dN). Input-output
channels with the same experiment name, input name, and output n ame
are always plotted in the same plot.
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