scipy.signal.ellipap(N, rp, rs)[source]#

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 -rp.

See also


Filter design function using this prototype



Lutovac, Tosic, and Evans, “Filter Design for Signal Processing”, Chapters 5 and 12.


Orfanidis, “Lecture Notes on Elliptic Filter Design”,