control.NyquistResponseData

class control.NyquistResponseData(count, contour, response, dt, sysname=None, return_contour=False)

Bases: object

Nyquist response data object.

Nyquist contour analysis allows the stability and robustness of a closed loop linear system to be evaluated using the open loop response of the loop transfer function. The NyquistResponseData class is used by the nyquist_response function to return the response of a linear system along the Nyquist ‘D’ contour. The response object can be used to obtain information about the Nyquist response or to generate a Nyquist plot.

Parameters

countinteger

Number of encirclements of the -1 point by the Nyquist curve for a system evaluated along the Nyquist contour.

contourcomplex array

The Nyquist ‘D’ contour, with appropriate indentations to avoid open loop poles and zeros near/on the imaginary axis.

responsecomplex array

The value of the linear system under study along the Nyquist contour.

dtNone or float

The system timebase.

sysnamestr

The name of the system being analyzed.

return_contourbool

If True, when the object is accessed as an iterable return two elements: count (number of encirclements) and contour. If False (default), then return only count.

Methods

plot	Plot a list of Nyquist responses.

plot(*args, **kwargs)

Plot a list of Nyquist responses.

See nyquist_plot for details.