control.matlab.nichols

control.matlab.nichols(data, omega=None, *fmt, grid=None, title=None, ax=None, label=None, **kwargs)

Nichols plot for a system.

Plots a Nichols plot for the system over a (optional) frequency range.

Parameters:

datalist of FrequencyResponseData or LTI

List of LTI systems or FrequencyResponseData objects. A single system or frequency response can also be passed.

omegaarray_like

Range of frequencies (list or bounds) in rad/sec.

*fmtmatplotlib.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).

gridboolean, optional

True if the plot should include a Nichols-chart grid. Default is True and can be set using config.defaults['nichols.grid'].

**kwargsmatplotlib.pyplot.plot keyword properties, optional

Additional keywords passed to matplotlib to specify line properties.

Returns:

cpltControlPlot object

Object containing the data that were plotted. See ControlPlot for more detailed information.

cplt.linesArray of matplotlib.lines.Line2D objects

Array containing information on 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.axes2D ndarray of matplotlib.axes.Axes

Axes for each subplot.

cplt.figurematplotlib.figure.Figure

Figure containing the plot.

cplt.legend2D array of matplotlib.legend.Legend

Legend object(s) contained in the plot.

Other Parameters:

axmatplotlib.axes.Axes, optional

The matplotlib axes to draw the figure on. If not specified and the current figure has a single axes, that axes is used. Otherwise, a new figure is created.

labelstr or array_like of str, optional

If present, replace automatically generated label(s) with given label(s). If sysdata is a list, strings should be specified for each system.

legend_locint or str, optional

Include a legend in the given location. Default is ‘upper left’, with no legend for a single response. Use False to suppress legend.

rcParamsdict

Override the default parameters used for generating plots. Default is set by config.defaults['ctrlplot.rcParams'].

show_legendbool, 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 the plot or legend_loc has been specified.

titlestr, optional

Set the title of the plot. Defaults to plot type and system name(s).