ellipap(N, rp, rs)¶
Return (z,p,k) of Nth-order elliptic analog lowpass filter.
The filter is a normalized prototype that has rp decibels of ripple in the passband and a stopband rs decibels down.
The filter’s angular (e.g. rad/s) cutoff frequency is normalized to 1, defined as the point at which the gain first drops below
- Filter design function using this prototype
 Lutova, Tosic, and Evans, “Filter Design for Signal Processing”, Chapters 5 and 12.