control.bode_plot

control.bode_plot(data, omega=None, *fmt, ax=None, omega_limits=None, omega_num=None, plot=None, plot_magnitude=True, plot_phase=None, overlay_outputs=None, overlay_inputs=None, phase_label=None, magnitude_label=None, label=None, display_margins=None, margins_method='best', title=None, sharex=None, sharey=None, **kwargs)[source]

Bode plot for a system.

Plot the magnitude and phase of the frequency response over a (optional) frequency range.

Parameters

data (list of FrequencyResponseData or LTI) – List of LTI systems or FrequencyResponseData objects. A single system or frequency response can also be passed.
omega (array_like, optoinal) – Set of frequencies in rad/sec to plot over. If not specified, this will be determined from the proporties of the systems. Ignored if data is not a list of systems.
*fmt (matplotlib.pyplot.plot() format string, optional) – Passed to matplotlib as the format string for all lines in the plot. The omega parameter must be present (use omega=None if needed).
dB (bool) – If True, plot result in dB. Default is False.
Hz (bool) – If True, plot frequency in Hz (omega must be provided in rad/sec). Default value (False) set by config.defaults[‘freqplot.Hz’].
deg (bool) – If True, plot phase in degrees (else radians). Default value (True) set by config.defaults[‘freqplot.deg’].
display_margins (bool or str) – If True, draw gain and phase margin lines on the magnitude and phase graphs and display the margins at the top of the graph. If set to ‘overlay’, the values for the gain and phase margin are placed on the graph. Setting display_margins turns off the axes grid.
**kwargs (matplotlib.pyplot.plot() keyword properties, optional) – Additional keywords passed to matplotlib to specify line properties.
ax (array of matplotlib.axes.Axes, optional) – The matplotlib axes to draw the figure on. If not specified, the axes for the current figure are used or, if there is no current figure with the correct number and shape of axes, a new figure is created. The shape of the array must match the shape of the plotted data.
freq_label (str, optional) – Labels to use for the frequency, magnitude, and phase axes. Defaults are set by config.defaults[‘freqplot.<keyword>’].
magnitude_label (str, optional) – Labels to use for the frequency, magnitude, and phase axes. Defaults are set by config.defaults[‘freqplot.<keyword>’].
phase_label (str, optional) – Labels to use for the frequency, magnitude, and phase axes. Defaults are set by config.defaults[‘freqplot.<keyword>’].
grid (bool, optional) – If True, plot grid lines on gain and phase plots. Default is set by config.defaults[‘freqplot.grid’].
initial_phase (float, optional) – Set the reference phase to use for the lowest frequency. If set, the initial phase of the Bode plot will be set to the value closest to the value specified. Units are in either degrees or radians, depending on the deg parameter. Default is -180 if wrap_phase is False, 0 if wrap_phase is True.
label (str or array_like of str, optional) – If present, replace automatically generated label(s) with the given label(s). If sysdata is a list, strings should be specified for each system. If MIMO, strings required for each system, output, and input.
legend_map (array of str, optional) – Location of the legend for multi-axes plots. Specifies an array of legend location strings matching the shape of the subplots, with each entry being either None (for no legend) or a legend location string (see legend()).
legend_loc (int or str, optional) – Include a legend in the given location. Default is ‘center right’, with no legend for a single response. Use False to suppress legend.
margins_method (str, optional) – Method to use in computing margins (see stability_margins()).
omega_limits (array_like of two values) – Set limits for plotted frequency range. If Hz=True the limits are in Hz otherwise in rad/s. Specifying omega as a list of two elements is equivalent to providing omega_limits. Ignored if data is not a list of systems.
omega_num (int) – Number of samples to use for the frequeny range. Defaults to config.defaults[‘freqplot.number_of_samples’]. Ignored if data is not a list of systems.
overlay_inputs (bool, optional) – If set to True, combine input and/or output signals onto a single plot and use line colors, labels, and a legend to distinguish them.
overlay_outputs (bool, optional) – If set to True, combine input and/or output signals onto a single plot and use line colors, labels, and a legend to distinguish them.
plot (bool, optional) – (legacy) If given, bode_plot returns the legacy return values of magnitude, phase, and frequency. If False, just return the values with no plot.
plot_magnitude (bool, optional) – If set to False, don’t plot the magnitude or phase, respectively.
plot_phase (bool, optional) – If set to False, don’t plot the magnitude or phase, respectively.
rcParams (dict) – Override the default parameters used for generating plots. Default is set by config.default[‘ctrlplot.rcParams’].
share_frequency (str or bool, optional) – Determine whether and how axis limits are shared between the indicated variables. Can be set set to ‘row’ to share across all subplots in a row, ‘col’ to set across all subplots in a column, or False to allow independent limits. Note: if sharex is given, it sets the value of share_frequency; if sharey is given, it sets the value of both share_magnitude and share_phase. Default values are ‘row’ for share_magnitude and share_phase’, ‘col’, for `share_frequency, and can be set using config.defaults[‘freqplot.share_<axis>’].
share_magnitude (str or bool, optional) – Determine whether and how axis limits are shared between the indicated variables. Can be set set to ‘row’ to share across all subplots in a row, ‘col’ to set across all subplots in a column, or False to allow independent limits. Note: if sharex is given, it sets the value of share_frequency; if sharey is given, it sets the value of both share_magnitude and share_phase. Default values are ‘row’ for share_magnitude and share_phase’, ‘col’, for `share_frequency, and can be set using config.defaults[‘freqplot.share_<axis>’].
share_phase (str or bool, optional) – Determine whether and how axis limits are shared between the indicated variables. Can be set set to ‘row’ to share across all subplots in a row, ‘col’ to set across all subplots in a column, or False to allow independent limits. Note: if sharex is given, it sets the value of share_frequency; if sharey is given, it sets the value of both share_magnitude and share_phase. Default values are ‘row’ for share_magnitude and share_phase’, ‘col’, for `share_frequency, and can be set using config.defaults[‘freqplot.share_<axis>’].
show_legend (bool, optional) – Force legend to be shown if True or hidden if False. If None, then show legend when there is more than one line on an axis or legend_loc or legend_map has been specified.
title (str, optional) – Set the title of the plot. Defaults to plot type and system name(s).
title_frame (str, optional) – Set the frame of reference used to center the plot title. If set to ‘axes’ (default), the horizontal position of the title will be centered relative to the axes. If set to ‘figure’, it will be centered with respect to the figure (faster execution).
wrap_phase (bool or float) – If wrap_phase is False (default), then the phase will be unwrapped so that it is continuously increasing or decreasing. If wrap_phase is True the phase will be restricted to the range [-180, 180) (or [ $-\pi$ , $\pi$ ) radians). If wrap_phase is specified as a float, the phase will be offset by 360 degrees if it falls below the specified value. Default value is False and can be set using config.defaults[‘freqplot.wrap_phase’].
reset (The default values for Bode plot configuration parameters can be) –
dictionary (using the config.defaults) –
'bode'. (with module name) –

Returns

cplt –

Object containing the data that were plotted:

cplt.lines: Array of matplotlib.lines.Line2D objects for each line in the plot. The shape of the array matches the subplots shape and the value of the array is a list of Line2D objects in that subplot.

cplt.axes: 2D array of matplotlib.axes.Axes for the plot.

cplt.figure: matplotlib.figure.Figure containing the plot.

cplt.legend: legend object(s) contained in the plot

See ControlPlot for more detailed information.

Return type

ControlPlot object