cupyx.scipy.signal.lp2bs#

cupyx.scipy.signal.lp2bs(b, a, wo=1.0, bw=1.0)[source]#

Transform a lowpass filter prototype to a bandstop filter.

Return an analog band-stop filter with center frequency wo and bandwidth bw from an analog low-pass filter prototype with unity cutoff frequency, in transfer function (‘ba’) representation.

Parameters:
  • b (array_like) – Numerator polynomial coefficients.

  • a (array_like) – Denominator polynomial coefficients.

  • 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:

  • b (array_like) – Numerator polynomial coefficients of the transformed band-stop filter.

  • a (array_like) – Denominator polynomial coefficients of the transformed band-stop filter.

Notes

This is derived from the s-plane 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.