scipy.signal.lp2hp_zpk¶

scipy.signal.
lp2hp_zpk
(z, p, k, wo=1.0)[source]¶ Transform a lowpass filter prototype to a highpass filter.
Return an analog highpass filter with cutoff frequency wo from an analog lowpass 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 highpass filter transfer function.
 p : ndarray
Poles of the transformed highpass filter transfer function.
 k : float
System gain of the transformed highpass filter.
Notes
This is derived from the splane 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.