cheb1ord Minimum filter order of a digital Chebyshev type I filter with the desired response characteristics. n = cheb1ord(Wp, Ws, Rp, Rs) [n, Wp] = cheb1ord(Wp, Ws, Rp, Rs) Wp: scalar or vector of length 2 (passband edge(s)), all elements must be in the range [0,1] Ws: scalar or vector of length 2 (stopband edge(s)), all elements must be in the range [0,1] Rp: passband ripple in dB. Rs: stopband attenuation in dB. n: Minimum filter order satisfying specs. This function computes the minimum filter order of a Chebyshev type I filter with the desired response characteristics. Stopband frequency ws and passband frequency wp specify the the filter frequency band edges. Frequencies are normalized to the Nyquist frequency in the range [0,1]. Rp is measured in decibels and is the allowable passband ripple and Rs is also measured in decibels and is the minimum attenuation in the stop band. If ws>wp then the filter is a low pass filter. If wp>ws, then the filter is a high pass filter. If wp and ws are vectors of length 2, then the passband interval is defined by wp and the stopband interval is defined by ws. If wp is contained within the lower and upper limits of ws, the filter is a band-pass filter. If ws is contained within the lower and upper limits of wp, the filter is a band-stop or band-reject filter. Sonu Sharma, RGIT Mumbai (fellow at FOSSEE, IIT Bombay)