scipy.signal.cheb1ord

scipy.signal.cheb1ord(wp, ws, gpass, gstop, analog=0)

Chebyshev type I filter order selection.

Return the order of the lowest order digital Chebyshev Type I filter that loses no more than gpass dB in the passband and has at least gstop dB attenuation in the stopband.

Parameters :

wp, ws – Passband and stopband edge frequencies, normalized from 0 :

to 1 (1 corresponds to pi radians / sample). For example:

Lowpass: wp = 0.2, ws = 0.3 Highpass: wp = 0.3, ws = 0.2 Bandpass: wp = [0.2, 0.5], ws = [0.1, 0.6] Bandstop: wp = [0.1, 0.6], ws = [0.2, 0.5]

gpass – The maximum loss in the passband (dB). :

gstop – The minimum attenuation in the stopband (dB). :

analog – Non-zero to design an analog filter (in this case wp and :

ws are in radians / second).

Returns :

ord – The lowest order for a Chebyshev type I filter that meets specs. :

Wn – The Chebyshev natural frequency (the “3dB frequency”) for :

use with scipy.signal.cheby1 to give filter results.