`scipy.signal._filter_design:cheb2ap`

Signature

def cheb2ap(N, rs, *, xp = None, device = None)

Return (z,p,k) for Nth-order Chebyshev type II analog lowpass filter.

The returned filter prototype has attenuation of at least rs decibels in the stopband.

The filter's angular (e.g. rad/s) cutoff frequency is normalized to 1, defined as the point at which the attenuation first reaches rs.

N : int: The order of the filter
rs : float: The attenuation in the stopband
xp : array_namespace, optional: Optional array namespace. Should be compatible with the array API standard, or supported by array-api-compat. Default: numpy
device : any: optional device specification for output. Should match one of the supported device specification in xp.