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# scipy.signal.cheb1ord

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

  Chebyshev type I filter order selection.

  Return the order of the lowest order digital or analog 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 : float Passband and stopband edge frequencies. For digital filters, these are normalized from 0 to 1, where 1 is the Nyquist frequency, pi radians / sample. (wp and ws are thus in half-cycles / 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] For analog filters, wp and ws are in radians / second. gpass : float The maximum loss in the passband (dB). gstop : float The minimum attenuation in the stopband (dB). analog : bool, optional When True, return an analog filter, otherwise a digital filter is returned.
  Returns : | ord : int The lowest order for a Chebyshev type I filter that meets specs. wn : ndarray or float The Chebyshev natural frequency (the “3dB frequency”) for use with `cheby1` to give filter results.

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