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scipy.signal.bode

scipy.signal.bode(system, w=None, n=100)

Calculate bode magnitude and phase data of a continuous-time system.

New in version 0.11.0.

Parameters :

system : an instance of the LTI class or a tuple describing the system.

The following gives the number of elements in the tuple and the interpretation:

• 2 (num, den)
• 3 (zeros, poles, gain)
• 4 (A, B, C, D)

w : array_like, optional

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.

n : int, optional

Number of frequency points to compute if w is not given. The n frequencies are logarithmically spaced in the range from two orders of magnitude before the minimum (slowest) pole to two orders of magnitude after the maximum (fastest) pole.

Returns :

w : 1D ndarray

Frequency array [rad/s]

mag : 1D ndarray

Magnitude array [dB]

phase : 1D ndarray

Phase array [deg]

Examples

>>> from scipy import signal
>>> import matplotlib.pyplot as plt

>>> s1 = signal.lti([1], [1, 1])
>>> w, mag, phase = signal.bode(s1)

>>> plt.figure()
>>> plt.semilogx(w, mag)    # bode magnitude plot
>>> plt.figure()
>>> plt.semilogx(w, phase)  # bode phase plot
>>> plt.show()

(Source code)