com.planetj.taste.impl.common
Class CompactRunningAverage

java.lang.Object
  com.planetj.taste.impl.common.CompactRunningAverage

All Implemented Interfaces:

RunningAverage, java.io.Serializable

Direct Known Subclasses:

CompactRunningAverageAndStdDev

public class CompactRunningAverage
extends java.lang.Object
implements RunningAverage, java.io.Serializable

Like FullRunningAverage but uses smaller values (short, float) to conserve memory. This is used in SlopeOneRecommender since it may allocate tens of millions of such objects.

Since:

1.3.1

Author:

Sean Owen

See Also:

Serialized Form

Constructor Summary

CompactRunningAverage()

Method Summary

void	addDatum(double datum)
void	changeDatum(double delta)
double	getAverage()
int	getCount()
void	removeDatum(double datum)
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

CompactRunningAverage

public CompactRunningAverage()

Method Detail

addDatum

public void addDatum(double datum)

Specified by:

addDatum in interface RunningAverage

Parameters:

datum - new item to add to the running average

removeDatum

public void removeDatum(double datum)

Specified by:

removeDatum in interface RunningAverage

Parameters:

datum - item to remove to the running average

changeDatum

public void changeDatum(double delta)

Specified by:

changeDatum in interface RunningAverage

Parameters:

delta - amount by which to change a datum in the running average

getCount

public int getCount()

Specified by:

getCount in interface RunningAverage

getAverage

public double getAverage()

Specified by:

getAverage in interface RunningAverage

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object