control.bode_plot¶
-
control.
bode_plot
(syslist, omega=None, plot=True, omega_limits=None, omega_num=None, margins=None, *args, **kwargs)¶ Bode plot for a system
Plots a Bode plot for the system over a (optional) frequency range.
- Parameters
syslist (linsys) – List of linear input/output systems (single system is OK)
omega (list) – List of frequencies in rad/sec to be used for frequency response
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[‘bode.Hz’]
deg (bool) – If True, plot phase in degrees (else radians). Default value (True) config.defaults[‘bode.deg’]
plot (bool) – If True (default), plot magnitude and phase
omega_limits (tuple, list, .. of two values) – Limits of the to generate frequency vector. If Hz=True the limits are in Hz otherwise in rad/s.
omega_num (int) – Number of samples to plot. Defaults to config.defaults[‘freqplot.number_of_samples’].
margins (bool) – If True, plot gain and phase margin.
*args (
matplotlib.pyplot.plot()
positional properties, optional) – Additional arguments for matplotlib plots (color, linestyle, etc)**kwargs (
matplotlib.pyplot.plot()
keyword properties, optional) – Additional keywords (passed to matplotlib)
- Returns
mag (array (list if len(syslist) > 1)) – magnitude
phase (array (list if len(syslist) > 1)) – phase in radians
omega (array (list if len(syslist) > 1)) – frequency in rad/sec
- Other Parameters
grid (bool) – If True, plot grid lines on gain and phase plots. Default is set by config.defaults[‘bode.grid’].
The default values for Bode plot configuration parameters can be reset using the config.defaults dictionary, with module name ‘bode’.
Notes
Alternatively, you may use the lower-level method
(mag, phase, freq) = sys.freqresp(freq)
to generate the frequency response for a system, but it returns a MIMO response.If a discrete time model is given, the frequency response is plotted along the upper branch of the unit circle, using the mapping z = exp(j omega dt) where omega ranges from 0 to pi/dt and dt is the discrete timebase. If not timebase is specified (dt = True), dt is set to 1.
Examples
>>> sys = ss("1. -2; 3. -4", "5.; 7", "6. 8", "9.") >>> mag, phase, omega = bode(sys)