scipy.signal.lp2hp_zpk

scipy.signal.lp2hp_zpk(z, p, k, wo=1.0)

Transform a lowpass filter prototype to a highpass filter.

Return an analog high-pass filter with cutoff frequency wo 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 cutoff, as angular frequency (e.g. rad/s). Defaults to no change.

Returns:

z : ndarray

Zeros of the transformed high-pass filter transfer function.

p : ndarray

Poles of the transformed high-pass filter transfer function.

k : float

System gain of the transformed high-pass filter.

See also

lp2lp_zpk, lp2bp_zpk, lp2bs_zpk, bilinear, lp2hp

Notes

This is derived from the s-plane substitution

\[s \rightarrow \frac{\omega_0}{s}\]

This maintains symmetry of the lowpass and highpass responses on a logarithmic scale.

New in version 1.1.0.