generates a Bode plot of a linear time-invariant system lsys.


plots for the frequency range ωmin to ωmax.


plots expr using the variable ω.

Details and Options

  • BodePlot plots the magnitude and phase of the transfer function of lsys.
  • The system lsys can be TransferFunctionModel or StateSpaceModel, including descriptor and delay systems.
  • For a system lsys with the corresponding transfer function , the following expressions are plotted:
  • continuous-time system
    discrete-time system with sample time
  • BodePlot treats the variable ω as local, effectively using Block.
  • BodePlot has the same options as Plot, with the following changes and additions:
  • ExclusionsNonefrequencies to exclude
    FeedbackType"Negative"the feedback type
    FrameTruewhether to draw a frame around each plot
    MeshFunctions{{#1&},{#1&}}how to determine the placement of mesh divisions
    PhaseRangeAutomaticrange of phase values to use
    PlotLayout"VerticalGrid"the layout to be used
    PlotRange{{Full,Automatic},{Full,Automatic}}range of values to include
    SamplingPeriodNonethe sampling period
    ScalingFunctions{{"Log10","dB"},{"Log10","Degree"}}the scaling functions
    StabilityMarginsFalsewhether to show the stability margins
    StabilityMarginsStyleAutomaticgraphics directives to specify the style of the stability margins
  • Possible explicit settings for the option PlotLayout are "VerticalGrid" and "List".
  • The option PlotLayout accepts the following values:
  • "VerticalGrid"magnitude and phase plot in a vertical grid
    "List"magnitude and phase plot in a list
    "Magnitude"magnitude plot only
    "Phase"phase plot only
  • The other options of BodePlot can be specified as a list of two elements, with the first element corresponding to the magnitude plot and the second to the phase plot.
  • Option specifications include:
  • opt->valuse val for both the magnitude and the phase plot
    opt->{val}use val for the magnitude plot and the default for the phase plot
    opt->{val1,val2}use val1 for the magnitude plot and val2 for the phase plot
    opt->{Automatic,val}use the default for the magnitude plot and val for the phase plot
  • With the PlotLayout settings "Magnitude" or "Phase", a single setting refers to the plot requested.
  • The scaling functions can be specified as ScalingFunctions->{{magfreqscale,magscale},{phasefreqscale,phasescale}}.
  • The frequency scales magfreqscale and phasefreqscale can be "Log10" or "Linear", which correspond to the base-10 logarithmic scale and linear scale, respectively.
  • The magnitude scale magscale can be "dB" or "Absolute", which correspond to the decibel and absolute values of the magnitude, respectively.
  • The phase scale phasescale can be "Degree" or "Radian".


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Basic Examples  (3)

The Bode plot of a system:

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A second-order system:

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Plot over an explicit frequency range:

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Bode plot of a state-space model:

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Scope  (13)

Generalizations & Extensions  (1)

Options  (21)

Applications  (7)

Properties & Relations  (1)

Introduced in 2010
Updated in 2014