iir1_design

Design of a single pole lowpass IIR filter.

Calling sequence

g = iir1_design('fc', fc);
g = iir1_design('tc', tc);
[g,h] = iir1_design(...);

Parameters

tp:

type of design parameter ('fc' for cutoff frequency or 'tc' for time constant)

fc:

Normalized cut-off frequency (between 0 and 0.5)

tc:

Time constant, in samples

g:

Forget factor

h:

Filter transfert function (z transform, rationnal function)

Description

Compute the forget factor of a first order lowpass IIR filter (and optionnaly the whole transfert function), of equation:

Example

// Set Fcut-off = 0.1 * sample rate
[g,h] = iir1_design('fc', 0.1);
[xm,fr] = frmag(h,512);
clf(); plot(fr,xm);

Magnitude response of a IIR1 lowpass filter designed with iir1_design