# scipy.signal.ellipap

scipy.signal.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 `-rp`.

  See also

  `ellip`

    Filter design function using this prototype

  References

  [1]

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

  [2]

  Orfanidis, “Lecture Notes on Elliptic Filter Design”, https://www.ece.rutgers.edu/~orfanidi/ece521/notes.pdf