base class template for Infinite Impulse Response filter (IIR) More...

#include <gri_iir.h>

Public Member Functions
	gri_iir (const std::vector< tap_type > &fftaps, const std::vector< tap_type > &fbtaps) throw (std::invalid_argument)
	Construct an IIR with the given taps.
	gri_iir ()
	~gri_iir ()
o_type	filter (const i_type input)
	compute a single output value.
void	filter_n (o_type output[], const i_type input[], long n)
	compute an array of N output values. `input` must have N valid entries.
unsigned	ntaps_ff () const
unsigned	ntaps_fb () const
void	set_taps (const std::vector< tap_type > &fftaps, const std::vector< tap_type > &fbtaps) throw (std::invalid_argument)
	install new taps.

Protected Attributes
std::vector< tap_type >	d_fftaps
std::vector< tap_type >	d_fbtaps
int	d_latest_n
int	d_latest_m
std::vector< tap_type >	d_prev_output
std::vector< i_type >	d_prev_input

Detailed Description

template<class i_type, class o_type, class tap_type>
class gri_iir< i_type, o_type, tap_type >

base class template for Infinite Impulse Response filter (IIR)

Constructor & Destructor Documentation

template<class i_type, class o_type, class tap_type>

gri_iir< i_type, o_type, tap_type >::gri_iir	(	const std::vector< tap_type > &	fftaps,
		const std::vector< tap_type > &	fbtaps
	)		throw (std::invalid_argument)

inline

Construct an IIR with the given taps.

This filter uses the Direct Form I implementation, where
\p fftaps contains the feed-forward taps, and \p fbtaps the feedback ones.

\p fftaps and \p fbtaps must have equal numbers of taps

The input and output satisfy a difference equation of the form

$y[n] - \sum_{k=1}^{M} a_k y[n-k] = \sum_{k=0}^{N} b_k x[n-k]$

with the corresponding rational system function

$H(z) = \frac{\sum_{k=0}^{N} b_k z^{-k}}{1 - \sum_{k=1}^{M} a_k z^{-k}}$

Note that some texts define the system function with a + in the denominator.
If you're using that convention, you'll need to negate the feedback taps.

template<class i_type, class o_type, class tap_type>

gri_iir< i_type, o_type, tap_type >::gri_iir ( )

inline

template<class i_type, class o_type, class tap_type>

gri_iir< i_type, o_type, tap_type >::~gri_iir ( )

inline

Member Function Documentation

template<class i_type, class o_type , class tap_type >

o_type gri_iir< i_type, o_type, tap_type >::filter ( const i_type input )

compute a single output value.

Returns:: the filtered input value.

template<class i_type, class o_type, class tap_type >

void gri_iir< i_type, o_type, tap_type >::filter_n	(	o_type	output[],
		const i_type	input[],
		long	n
	)

compute an array of N output values. input must have N valid entries.

template<class i_type, class o_type, class tap_type>

unsigned gri_iir< i_type, o_type, tap_type >::ntaps_fb ( ) const

inline

template<class i_type, class o_type, class tap_type>

unsigned gri_iir< i_type, o_type, tap_type >::ntaps_ff ( ) const

inline

Returns:: number of taps in filter.

template<class i_type, class o_type, class tap_type>

void gri_iir< i_type, o_type, tap_type >::set_taps	(	const std::vector< tap_type > &	fftaps,
		const std::vector< tap_type > &	fbtaps
	)		throw (std::invalid_argument)