Package lejos.robotics.filter

Class LowPassFilter

java.lang.Object

lejos.robotics.filter.AbstractFilter

lejos.robotics.filter.LowPassFilter

All Implemented Interfaces:

SampleProvider

public class LowPassFilter
extends AbstractFilter

Provides a low-pass filter for samples

See Also:

http://en.wikipedia. org/wiki/Low-pass_filter

Field Summary

Fields

Modifier and Type	Field and Description
(package private) long	lastTime
(package private) float[]	smoothed
(package private) float	timeConstant

Fields inherited from class lejos.robotics.filter.AbstractFilter

sampleSize, source

Constructor Summary

Constructors

Constructor and Description
LowPassFilter(SampleProvider source, float timeConstant) Constructor

Method Summary

Modifier and Type	Method and Description
void	fetchSample(float[] dst, int off) Fetches a sample from the source and low-passes it See http://en.wikipedia.org/wiki/Low-pass_filter
void	setTimeConstant(float timeConstant)

Methods inherited from class lejos.robotics.filter.AbstractFilter

sampleSize

Methods inherited from class java.lang.Object

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

Field Detail

smoothed

float[] smoothed

lastTime

long lastTime

timeConstant

float timeConstant

Constructor Detail

LowPassFilter

public LowPassFilter(SampleProvider source,
                     float timeConstant)

Constructor

Parameters:

source - The source for getting samples

timeConstant - The cut-off frequency for the filter

Method Detail

fetchSample

public void fetchSample(float[] dst,
                        int off)

Fetches a sample from the source and low-passes it See http://en.wikipedia.org/wiki/Low-pass_filter

Specified by:

fetchSample in interface SampleProvider

Overrides:

fetchSample in class AbstractFilter

Parameters:

dst - The array to store the sample in.

off - The elements of the sample are stored in the array starting at the offset position.

setTimeConstant

public void setTimeConstant(float timeConstant)