# scipy.signal.lp2lp_zpk#

scipy.signal.lp2lp_zpk(z, p, k, wo=1.0)[source]#

Transform a lowpass filter prototype to a different frequency.

Return an analog low-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:
zarray_like

Zeros of the analog filter transfer function.

parray_like

Poles of the analog filter transfer function.

kfloat

System gain of the analog filter transfer function.

wofloat

Desired cutoff, as angular frequency (e.g., rad/s). Defaults to no change.

Returns:
zndarray

Zeros of the transformed low-pass filter transfer function.

pndarray

Poles of the transformed low-pass filter transfer function.

kfloat

System gain of the transformed low-pass filter.

Notes

This is derived from the s-plane substitution

$s \rightarrow \frac{s}{\omega_0}$

New in version 1.1.0.