gsignal (version 0.3-7)

ellipap: Low-pass analog elliptic filter

Description

Return the zeros, poles and gain of an analog elliptic low-pass filter prototype.

Usage

ellipap(n, Rp, Rs)

Value

list of class Zpg containing zeros, poles and gain of the filter.

Arguments

n

Order of the filter.

Rp

dB of passband ripple.

Rs

dB of stopband ripple.

Author

Carne Draug, . Conversion to R by Geert van Boxtel, .

Details

This function exists for compatibility with 'Matlab' and 'OCtave' only, and is equivalent to ellip(n, Rp, Rs, 1, "low", "s").

Examples

## 9th order elliptic low-pass analog filter
zp <- ellipap(9, .1, 40)
w <- seq(0, 4, length.out = 128)
freqs(zp, w)