freqresp(system, w=None, n=10000)
If (num, den) is passed in for system
, coefficients for both the numerator and denominator should be specified in descending exponent order (e.g. s^2 + 3s + 5
would be represented as [1, 3, 5]
).
The following gives the number of elements in the tuple and the interpretation:
1 (instance of
lti)2 (num, den)
3 (zeros, poles, gain)
4 (A, B, C, D)
Array of frequencies (in rad/s). Magnitude and phase data is calculated for every value in this array. If not given, a reasonable set will be calculated.
Number of frequency points to compute if w is not given. The n frequencies are logarithmically spaced in an interval chosen to include the influence of the poles and zeros of the system.
Calculate the frequency response of a continuous-time system.
Generating the Nyquist plot of a transfer function
>>> from scipy import signal
... import matplotlib.pyplot as plt
Construct the transfer function $H(s) = \frac{5}{(s-1)^3}$ :
>>> s1 = signal.ZerosPolesGain([], [1, 1, 1], [5])
>>> w, H = signal.freqresp(s1)
>>> plt.figure()
... plt.plot(H.real, H.imag, "b")
... plt.plot(H.real, -H.imag, "r")
... plt.show()
The following pages refer to to this document either explicitly or contain code examples using this.
scipy.signal._ltisys.lti.freqresp
scipy.signal._ltisys.freqresp
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