org.apache.solr.util.stats
Class UniformSample

java.lang.Object
  org.apache.solr.util.stats.UniformSample

All Implemented Interfaces:

Sample

public class UniformSample
extends Object
implements Sample

A random sample of a stream of longs. Uses Vitter's Algorithm R to produce a statistically representative sample.

See Also:

Random Sampling with a Reservoir

Constructor Summary

UniformSample(int reservoirSize)
Creates a new UniformSample.

Method Summary

void	clear() Clears all recorded values.
Snapshot	getSnapshot() Returns a snapshot of the sample's values.
int	size() Returns the number of values recorded.
void	update(long value) Adds a new recorded value to the sample.

Methods inherited from class java.lang.Object

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

Constructor Detail

UniformSample

public UniformSample(int reservoirSize)

Creates a new UniformSample.

Parameters:

reservoirSize - the number of samples to keep in the sampling reservoir

Method Detail

clear

public void clear()

Description copied from interface: Sample

Clears all recorded values.

Specified by:

clear in interface Sample

size

public int size()

Description copied from interface: Sample

Returns the number of values recorded.

Specified by:

size in interface Sample

Returns:

the number of values recorded

update

public void update(long value)

Description copied from interface: Sample

Adds a new recorded value to the sample.

Specified by:

update in interface Sample

Parameters:

value - a new recorded value

getSnapshot

public Snapshot getSnapshot()

Description copied from interface: Sample

Returns a snapshot of the sample's values.

Specified by:

getSnapshot in interface Sample

Returns:

a snapshot of the sample's values