control.phase_crossover_frequencies

control.phase_crossover_frequencies(sys)

Compute frequencies and gains at intersections with real axis in Nyquist plot.

Parameters

sys (SISO LTI system) –

Returns

  • omega (ndarray) – 1d array of (non-negative) frequencies where Nyquist plot intersects the real axis

  • gain (ndarray) – 1d array of corresponding gains

Examples

>>> tf = TransferFunction([1], [1, 2, 3, 4])
>>> phase_crossover_frequencies(tf)
(array([ 1.73205081,  0.        ]), array([-0.5 ,  0.25]))