com.tagtraum.pcmsampledsp

Class FIRFilter

java.lang.Object

com.tagtraum.pcmsampledsp.FIRFilter

public class FIRFilter
extends Object

FIR (finite impulse response) filter.

To compute the coefficients you might want to use Matlab or the free package Octave (with additional Octave-Forge packages needed for signals). E.g. for a low pass filter you could execute:

 b = fir1(16,0.125)
 

Author:

Hendrik Schreiber

See Also:

Wikipedia on FIR

Constructor Summary

Constructors

Constructor and Description
FIRFilter(double[] coefficients)

Method Summary

Modifier and Type	Method and Description
protected void	addToDelayLine(double sample)
static FIRFilter	createFir1_29thOrderLowpass(int factor) 29th order Fir1 (Matlab/Octave) lowpass filter that lets factor-th-Nyquist pass (ω=1/factor).
boolean	equals(Object o)
protected double	filter()
float[]	filter(float[] data)
double[]	getCoefficients()
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

FIRFilter

public FIRFilter(double[] coefficients)

Method Detail

getCoefficients

public double[] getCoefficients()

filter

public float[] filter(float[] data)

addToDelayLine

protected void addToDelayLine(double sample)

filter

protected double filter()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

createFir1_29thOrderLowpass

public static FIRFilter createFir1_29thOrderLowpass(int factor)
                                             throws IllegalArgumentException

29th order Fir1 (Matlab/Octave) lowpass filter that lets factor-th-Nyquist pass (ω=1/factor). Supported factors are 2 to 10.

Parameters:

factor - factor

Returns:

filter

Throws:

IllegalArgumentException - if the factor is not supported.