Collaboration diagram for FIR filters:

Functions
void	FIRfilter (EST_Wave &in_sig, const EST_FVector &numerator, int delay_correction=0)

void	FIRfilter (const EST_Wave &in_sig, EST_Wave &out_sig, const EST_FVector &numerator, int delay_correction=0)

void	FIR_double_filter (EST_Wave &in_sig, EST_Wave &out_sig, const EST_FVector &numerator)

void	FIRlowpass_filter (EST_Wave &sigin, int freq, int order=DEFAULT_FILTER_ORDER)

void	FIRlowpass_filter (const EST_Wave &in_sig, EST_Wave &out_sig, int freq, int order=DEFAULT_FILTER_ORDER)

void	FIRhighpass_filter (EST_Wave &in_sig, int freq, int order)

void	FIRhighpass_filter (const EST_Wave &sigin, EST_Wave &out_sig, int freq, int order=DEFAULT_FILTER_ORDER)

void	FIRhighpass_double_filter (EST_Wave &sigin, int freq, int order=DEFAULT_FILTER_ORDER)

void	FIRhighpass_double_filter (const EST_Wave &int_sig, EST_Wave &out_sig, int freq, int order=DEFAULT_FILTER_ORDER)

void	FIRlowpass_double_filter (EST_Wave &sigin, int freq, int order=DEFAULT_FILTER_ORDER)

void	FIRlowpass_double_filter (const EST_Wave &in_sig, EST_Wave &out_sig, int freq, int order=DEFAULT_FILTER_ORDER)

Detailed Description

Finite impulse response (FIR) filters which are useful for band-pass, low-pass and high-pass filtering.

FIR filters perform the following operation:

$y_t=\sum_{i=0}^{O-1} c_i \; x_{t-i}$

where $O$ is the filter order, $c_i$ are the filter coefficients, $x_t$ is the input at time $t$ and $y_t$ is the output at time $t$ . Functions are provided for designing the filter (i.e. finding the coefficients).

Function Documentation

void FIRfilter	(	EST_Wave &	in_sig,
		const EST_FVector &	numerator,
		int	delay_correction = `0`
	)

General purpose FIR filter. This function will filter the waveform sig with a previously designed filter, given as numerator. The filter coefficients can be designed using one of the designed functions, e.g. design_FIR_filter.

See also: design_FIR_filter, design_lowpass_FIR_filter, design_highpass_FIR_filter,; FIRfilter, FIRlowpass_filter, FIRhighpass_filter

Definition at line 336 of file filter.cc.

void FIRfilter	(	const EST_Wave &	in_sig,
		EST_Wave &	out_sig,
		const EST_FVector &	numerator,
		int	delay_correction = `0`
	)

General purpose FIR filter. This function will filter the waveform sig with a previously designed filter, given as numerator. The filter coefficients can be designed using one of the designed functions, e.g. design_FIR_filter.

See also: design_FIR_filter, design_lowpass_FIR_filter, design_highpass_FIR_filter,; FIRfilter, FIRlowpass_filter, FIRhighpass_filter

Definition at line 349 of file filter.cc.

void FIR_double_filter	(	EST_Wave &	in_sig,
		EST_Wave &	out_sig,
		const EST_FVector &	numerator
	)

General purpose FIR double (zero-phase) filter. This function will double filter the waveform sig with a previously designed filter, given as numerator. The filter coefficients can be designed using one of the designed functions, e.g. design_FIR_filter. Double filtering is performed by filtering the signal normally, reversing the waveform, filtering again and reversing the waveform again. Normal filtering will impose a lag on the signal depending on the order of the filter. By filtering the signal forwards and backwards, the lags cancel each other out and the output signal is in phase with the input signal.

See also: design_FIR_filter, design_lowpass_FIR_filter, design_highpass_FIR_filter,; FIRfilter, FIRlowpass_filter, FIRhighpass_filter

Definition at line 408 of file filter.cc.

void FIRlowpass_filter	(	EST_Wave &	sigin,
		int	freq,
		int	order = `DEFAULT_FILTER_ORDER`
	)

Quick function for one-off low pass filtering. If repeated lowpass filtering is needed, first design the required filter using design_lowpass_filter, and then use FIRfilter to do the actual filtering.

See also: design_FIR_filter, design_lowpass_FIR_filter, design_highpass_FIR_filter, FIRfilter, FIRhighpass_filter, FIRlowpass_filter

Parameters

sigin	input waveform, which will be overwritten
freq
order	number of filter coefficients, eg. 99

Definition at line 526 of file filter.cc.

void FIRlowpass_filter	(	const EST_Wave &	in_sig,
		EST_Wave &	out_sig,
		int	freq,
		int	order = `DEFAULT_FILTER_ORDER`
	)

Quick function for one-off low pass filtering. If repeated lowpass filtering is needed, first design the required filter using design_lowpass_filter, and then use FIRfilter to do the actual filtering.

Parameters

in_sig	input waveform
out_sig	output waveform
freq	cutoff frequency in Hertz
order	number of filter coefficients , e.g. 99

See also: design_FIR_filter, design_lowpass_FIR_filter, design_highpass_FIR_filter, FIRfilter, FIRhighpass_filter

Definition at line 518 of file filter.cc.

void FIRhighpass_filter	(	EST_Wave &	in_sig,
		int	freq,
		int	order
	)

Quick function for one-off high pass filtering. If repeated lowpass filtering is needed, first design the required filter using design_lowpass_filter, and then use FIRfilter to do the actual filtering.

Parameters

in_sig	input waveform, which will be overwritten
freq	cutoff frequency in Hertz
order	number of filter coefficients, eg. 99

See also: design_FIR_filter, design_lowpass_FIR_filter, design_highpass_FIR_filter; FIRfilter, FIRlowpass_filter, FIRhighpass_filter

Definition at line 534 of file filter.cc.

void FIRhighpass_filter	(	const EST_Wave &	sigin,
		EST_Wave &	out_sig,
		int	freq,
		int	order = `DEFAULT_FILTER_ORDER`
	)

Quick function for one-off high pass filtering. If repeated highpass filtering is needed, first design the required filter using design_highpass_filter, and then use FIRfilter to do the actual filtering.

Parameters

in_sig	input waveform
out_sig	output waveform
freq	cutoff frequency in Hertz
order	number of filter coefficients, eg. 99

See also: design_FIR_filter, design_lowpass_FIR_filter, design_highpass_FIR_filter; FIRfilter, FIRlowpass_filter, FIRhighpass_filter

Definition at line 541 of file filter.cc.

void FIRhighpass_double_filter	(	EST_Wave &	sigin,
		int	freq,
		int	order = `DEFAULT_FILTER_ORDER`
	)

Quick function for one-off double low pass filtering.

Normal low pass filtering (FIRlowpass_filter) introduces a time delay. This function filters the signal twice, first forward and then backwards, which ensures a zero phase lag. Hence the order parameter need only be half what it is for (FIRlowpass_filter to achieve the same effect.

Parameters

in_sig	input waveform, which will be overwritten
freq	cutoff frequency in Hertz
order	number of filter coefficients, eg. 99

See also: FIRhighpass_filter

Definition at line 584 of file filter.cc.

void FIRhighpass_double_filter	(	const EST_Wave &	int_sig,
		EST_Wave &	out_sig,
		int	freq,
		int	order = `DEFAULT_FILTER_ORDER`
	)

Quick function for one-off double low pass filtering.

Normal low pass filtering (FIRlowpass_filter) introduces a time delay. This function filters the signal twice, first forward and then backwards, which ensures a zero phase lag. Hence the order parameter need only be half what it is for (FIRlowpass_filter) to achieve the same effect.

Parameters

in_sig	input waveform
out_sig	output waveform
freq	cutoff frequency in Hertz
order	number of filter coefficients, eg. 99

See also: FIRhighpass_filter

Definition at line 572 of file filter.cc.

void FIRlowpass_double_filter	(	EST_Wave &	sigin,
		int	freq,
		int	order = `DEFAULT_FILTER_ORDER`
	)

Quick function for one-off zero phase high pass filtering.

Normal high pass filtering (FIRhighpass_filter) introduces a time delay. This function filters the signal twice, first forward and then backwards, which ensures a zero phase lag. Hence the order parameter need only be half what it is for (FIRhighpass_filter) to achieve the same effect.

Parameters

in_sig	input waveform, which will be overwritten
freq	cutoff frequency in Hertz
order	number of filter coefficients, eg. 99

See also: FIRlowpass_filter

Definition at line 549 of file filter.cc.

void FIRlowpass_double_filter	(	const EST_Wave &	in_sig,
		EST_Wave &	out_sig,
		int	freq,
		int	order = `DEFAULT_FILTER_ORDER`
	)

Quick function for one-off zero phase high pass filtering.

Normal high pass filtering (FIRhighpass_filter) introduces a time delay. This function filters the signal twice, first forward and then backwards, which ensures a zero phase lag. Hence the order parameter need only be half what it is for (FIRhighpass_filter) to achieve the same effect.

Parameters

in_sig	input waveform
out_sig	output waveform
freq	cutoff frequency in Hertz
order	number of filter coefficients, eg. 99

See also: FIRlowpass_filter

Definition at line 560 of file filter.cc.