ellipap Produces a lowpass analog elliptic prototype filter. [z, p, g] = ellipap (n, Rp, Rs) n: Filter Order Rp: Peak-to-peak passband ripple in dB Rs: Stopband attenuation in dB z: Zeros p: Poles g: Gain It gives a lowpass analog elliptic prototype filter of nth order, with a Peak-to-peak passband ripple of Rp dB and a stopband attenuation of Rs dB. Sonu Sharma, RGIT Mumbai FOSSEE, IIT Bombay