signals.filters.iir-1

It can design three kinds of filters:

butterworthIIRFilter - Maximally flat passband, monotonic everywhere.
chebyshev1IIRFilter - Equiripple in the passband, monotonic in the stopband.
chebyshev2IIRFilter - Monotonic in the passband, equiripple in the stopband.

import signals.filters.iir-1;

IIR Filter Design


my_filter = IIRFilter (
	8, // filter order
	1 dB, // passband ripple
	-60 dB, // stopband attenuation
	"", // band configuration
	[ 25 Hz ], // cutting frequency
	 150 Hz  // sampling frequency
)
my_filter.plot()

All IIR filter design functions return signals.containers-1/ZeroPoleGain structures.

import signals.filters.iir-1;

Visualization


my_filter.plotZerosPoles()


my_filter.plotPhase()


my_filter.plotAmplitude()


my_filter.plotImpulseResponse()

import signals.filters.iir-1;

Testing the designed filter


input = [! zeros(100,1), ones(100,1), zeros(100,1), ones(100,1) !];
output = my_filter.filter(input);
chart().curve(input).curve(output)

import signals.filters.iir-1;

Implementation


my_filter.getImplementationDetails()

Library signals.filters.iir-1