Module « scipy.signal »

Fonction bode - module scipy.signal

Signature de la fonction bode

def bode(system, w=None, n=100) 

Description

bode.__doc__

    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]``).

    .. versionadded:: 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()