Module « scipy.signal »

Fonction lp2bs_zpk - module scipy.signal

Signature de la fonction lp2bs_zpk

def lp2bs_zpk(z, p, k, wo=1.0, bw=1.0) 

Description

lp2bs_zpk.__doc__

    Transform a lowpass filter prototype to a bandstop filter.

    Return an analog band-stop filter with center frequency `wo` and
    stopband width `bw` from an analog low-pass filter prototype with unity
    cutoff frequency, using zeros, poles, and gain ('zpk') representation.

    Parameters
    ----------
    z : array_like
        Zeros of the analog filter transfer function.
    p : array_like
        Poles of the analog filter transfer function.
    k : float
        System gain of the analog filter transfer function.
    wo : float
        Desired stopband center, as angular frequency (e.g., rad/s).
        Defaults to no change.
    bw : float
        Desired stopband width, as angular frequency (e.g., rad/s).
        Defaults to 1.

    Returns
    -------
    z : ndarray
        Zeros of the transformed band-stop filter transfer function.
    p : ndarray
        Poles of the transformed band-stop filter transfer function.
    k : float
        System gain of the transformed band-stop filter.

    See Also
    --------
    lp2lp_zpk, lp2hp_zpk, lp2bp_zpk, bilinear
    lp2bs

    Notes
    -----
    This is derived from the s-plane substitution

    .. math:: s \rightarrow \frac{s \cdot \mathrm{BW}}{s^2 + {\omega_0}^2}

    This is the "wideband" transformation, producing a stopband with
    geometric (log frequency) symmetry about `wo`.

    .. versionadded:: 1.1.0