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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.

  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: 1 (instance of `lti`) 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 an interval chosen to include the influence of the poles and zeros of the system.
  Returns: | w : 1D ndarray Frequency array [rad/s] mag : 1D ndarray Magnitude array [dB] phase : 1D ndarray Phase array [deg]

  Notes

  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]`).

  New in version 0.11.0.

  Examples

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

      >>> sys = signal.TransferFunction([1], [1, 1])
      >>> w, mag, phase = signal.bode(sys)

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

  (Source code)