Package Filters

Class FIRFilterMethod

java.lang.Object

Filters.FilterMethod

Filters.FIRFilterMethod

Direct Known Subclasses:

FIRArbitraryFilter

public class FIRFilterMethod
extends FilterMethod

FIR filter method, filter design uses a Cheychev window function.

Bit of a bodge to make it fit into the framework originally developed for IIR filters.

Since it uses the same parameter set as the IIR filters, the filter order for FIR filters will be 2^N-1.

Author:

Doug Gillespie

Field Summary

Fields

Modifier and Type	Field	Description
static final int	NRESPONSEPOINTS

Constructor Summary

Constructors

Constructor	Description
FIRFilterMethod(double sampleRate, FilterParams filterParams)

Method Summary

Modifier and Type	Method	Description
Filter	createFilter(int channel)
double	getFilterGain(double omega)	Get the filter gain at an angular frequency (o invalid input: '<' omega invalid input: '<' pi).
double	getFilterGainConstant()
double	getFilterPhase(double omega)	Get the filter phase at an angular frequency (o invalid input: '<' omega invalid input: '<' pi).
double[]	getFilterTaps()

Methods inherited from class Filters.FilterMethod

createFilterMethod, getFastFilterCoefficients, getFilterParams, getSampleRate, setFilterParams, setSampleRate

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

NRESPONSEPOINTS

public static final int NRESPONSEPOINTS

See Also:

• Constant Field Values

Constructor Details

FIRFilterMethod

public FIRFilterMethod(double sampleRate,
 FilterParams filterParams)

Method Details

getFilterGain

public double getFilterGain(double omega)

Description copied from class: FilterMethod

Get the filter gain at an angular frequency (o invalid input: '<' omega invalid input: '<' pi).

Specified by:

getFilterGain in class FilterMethod

Parameters:

omega - angular frequency

Returns:

gain

getFilterGainConstant

public double getFilterGainConstant()

Specified by:

getFilterGainConstant in class FilterMethod

Returns:

any additional gain constant (needed for IIRF's)

getFilterPhase

public double getFilterPhase(double omega)

Description copied from class: FilterMethod

Get the filter phase at an angular frequency (o invalid input: '<' omega invalid input: '<' pi).

Specified by:

getFilterPhase in class FilterMethod

Parameters:

omega - angular frequency

Returns:

phase

createFilter

public Filter createFilter(int channel)

Specified by:

createFilter in class FilterMethod

Parameters:

channel - channel number (used in filter book keeping)

Returns:

Create a filter object - which can actually do some filtering for us. Note that a filterMethod object may be asked to create multiple filters for multi-channel systems.

getFilterTaps

public double[] getFilterTaps()

Returns:

the filterTaps