iir - Iir digital filter (original) (raw)

Scilab 5.3.3

Please note that the recommended version of Scilab is 2026.0.1. This page might be outdated.
See the recommended documentation of this function

Scilab help >> Signal Processing > iir

Calling Sequence

[hz]=iir(n,ftype,fdesign,frq,delta)

Arguments

n

positive number witn inteher value, the filter order.

ftype

string specifying the filter type, the possible values are:'lp' for low-pass,'hp' for high pass,'bp' for band pass and'sb' for stop band.

fdesign

string specifying the analog filter design, the possible values are: 'butt','cheb1', 'cheb2' and'ellip'

frq

2-vector of discrete cut-off frequencies (i.e.,0<frq<.5). For 'lp' and'hp' filters only frq(1) is used. For 'bp' and 'sb' filtersfrq(1) is the lower cut-off frequency andfrq(2) is the upper cut-off frequency

delta

2-vector of error values for cheb1,cheb2, and ellip filters where only delta(1) is used forcheb1 case, only delta(2) is used for cheb2 case, anddelta(1) and delta(2) are both used for ellip case.0<delta(1),delta(2)<1

Examples

hz=iir(3,'bp','ellip',[.15 .25],[.08 .03]); [hzm,fr]=frmag(hz,256); plot2d(fr',hzm') xtitle('Discrete IIR filter band pass 0.15<fr<0.25 ',' ',' '); q=poly(0,'q');
hzd=horner(hz,1/q)

See Also