scipy.signal.lp2bs_zpk¶

scipy.signal.
lp2bs_zpk
(z, p, k, wo=1.0, bw=1.0)[source]¶ Transform a lowpass filter prototype to a bandstop filter.
Return an analog bandstop filter with center frequency wo and stopband width bw from an analog lowpass 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 stopband center, as angular frequency (e.g. rad/s). Defaults to no change.
 bwfloat
Desired stopband width, as angular frequency (e.g. rad/s). Defaults to 1.
 Returns
 zndarray
Zeros of the transformed bandstop filter transfer function.
 pndarray
Poles of the transformed bandstop filter transfer function.
 kfloat
System gain of the transformed bandstop filter.
Notes
This is derived from the splane substitution
\[s \rightarrow \frac{s \cdot \mathrm{BW}}{s^2 + {\omega_0}^2}\]This is the “wideband” transformation, producing a stopband with geometric (log frequency) symmetry about wo.
New in version 1.1.0.