cheb2ap {gsignal}

Chebyshev Type II filter prototype

Description

Return the poles and gain of an analog Chebyshev Type II lowpass filter prototype.

Usage

cheb2ap(n, Rs)

Arguments

n

Order of the filter.

Rs

dB of stop-band ripple.

Details

This function exists for compatibility with 'Matlab' and 'Octave' only, and is equivalent to cheby2(n, Rp, 1, "low", "s").

Value

list of class Zpg containing poles and gain of the filter

Author(s)

Carne Draug, [e-mail].
Conversion to R by Geert van Boxtel, [e-mail].

Examples

## 9th order Chebyshev type II low-pass analog filter
zp <- cheb2ap(9, 30)
w <- seq(0, 4, length.out = 128)
freqs(zp, w)