12.11. Plotting Bode Diagrams

The commands used to plot the Bode diagrams of LTI systems in MATLAB are

bode(n,d)
bode(sys)

where

n and d are polynomials representing numerator and denominator of the given transfer function, and sys is an LTI model of the system, created with either tf, zpk or ss functions as described earlier in this chapter.

The frequency range and number of points are automatically selected.

Another similar command is

bode (n, d, ω)

where ω specifies the user-defined frequency range in rad/sec.

When the output response values are to be stored separately in matrices, then the following command with left-hand arguments and frequency vector is used:

[mag, phase, ω]= bode (n , d, ω)

This command will not generate any plot. ...

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