weka.filters.unsupervised.instance

Class ReservoirSample

java.lang.Object

weka.filters.Filter

weka.filters.unsupervised.instance.ReservoirSample

All Implemented Interfaces:

Serializable, CapabilitiesHandler, OptionHandler, RevisionHandler, StreamableFilter, UnsupervisedFilter

public class ReservoirSample
extends Filter
implements UnsupervisedFilter, OptionHandler, StreamableFilter

Produces a random subsample of a dataset using the reservoir sampling Algorithm "R" by Vitter. The original data set does not have to fit into main memory, but the reservoir does.

BibTeX:

 @article{Vitter1985,
    author = {J. S. Vitter},
    journal = {ACM Transactions on Mathematical Software},
    number = {1}
    volume = {11}
    pages = {37-57},
    title = {Random Sampling with a Reservoir},
    year = {1985}
 }
 

Valid options are:

 -S <num>
  Specify the random number seed (default 1)
 

 -Z <num>
  The size of the output dataset - number of instances
  (default 100)
 

Version:

$Revision: 10215 $

Author:

Mark Hall (mhall{[at]}pentaho{[dot]}org)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ReservoirSample()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	batchFinished() Signify that this batch of input to the filter is finished.
Capabilities	getCapabilities() Returns the Capabilities of this filter.
String[]	getOptions() Gets the current settings of the filter.
int	getRandomSeed() Gets the random number seed.
String	getRevision() Returns the revision string.
int	getSampleSize() Gets the subsample size.
String	globalInfo() Returns a string describing this filter
boolean	input(Instance instance) Input an instance for filtering.
Enumeration<Option>	listOptions() Returns an enumeration describing the available options.
static void	main(String[] argv) Main method for testing this class.
String	randomSeedTipText() Returns the tip text for this property
String	sampleSizeTipText() Returns the tip text for this property
boolean	setInputFormat(Instances instanceInfo) Sets the format of the input instances.
void	setOptions(String[] options) Parses a given list of options.
void	setRandomSeed(int newSeed) Sets the random number seed.
void	setSampleSize(int newSampleSize) Sets the size of the subsample.

Methods inherited from class weka.filters.Filter

batchFilterFile, filterFile, getCapabilities, getOutputFormat, isFirstBatchDone, isNewBatch, isOutputFormatDefined, makeCopies, makeCopy, mayRemoveInstanceAfterFirstBatchDone, numPendingOutput, output, outputPeek, runFilter, toString, useFilter, wekaStaticWrapper

Methods inherited from class java.lang.Object

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

Constructor Detail

ReservoirSample

public ReservoirSample()

Method Detail

globalInfo

public String globalInfo()

Returns a string describing this filter

Returns:

a description of the classifier suitable for displaying in the explorer/experimenter gui

listOptions

public Enumeration<Option> listOptions()

Returns an enumeration describing the available options.

Specified by:

listOptions in interface OptionHandler

Returns:

an enumeration of all the available options.

setOptions

public void setOptions(String[] options)
                throws Exception

Parses a given list of options.

Valid options are:

 -S <num>
  Specify the random number seed (default 1)
 

 -Z <num>
  The size of the output dataset - number of instances
  (default 100)
 

Specified by:

setOptions in interface OptionHandler

Parameters:

options - the list of options as an array of strings

Throws:

Exception - if an option is not supported

getOptions

public String[] getOptions()

Gets the current settings of the filter.

Specified by:

getOptions in interface OptionHandler

Returns:

an array of strings suitable for passing to setOptions

randomSeedTipText

public String randomSeedTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

getRandomSeed

public int getRandomSeed()

Gets the random number seed.

Returns:

the random number seed.

setRandomSeed

public void setRandomSeed(int newSeed)

Sets the random number seed.

Parameters:

newSeed - the new random number seed.

sampleSizeTipText

public String sampleSizeTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

getSampleSize

public int getSampleSize()

Gets the subsample size.

Returns:

the subsample size

setSampleSize

public void setSampleSize(int newSampleSize)

Sets the size of the subsample.

Parameters:

newSampleSize - size of the subsample.

getCapabilities

public Capabilities getCapabilities()

Returns the Capabilities of this filter.

Specified by:

getCapabilities in interface CapabilitiesHandler

Overrides:

getCapabilities in class Filter

Returns:

the capabilities of this object

See Also:

Capabilities

setInputFormat

public boolean setInputFormat(Instances instanceInfo)
                       throws Exception

Sets the format of the input instances.

Overrides:

setInputFormat in class Filter

Parameters:

instanceInfo - an Instances object containing the input instance structure (any instances contained in the object are ignored - only the structure is required).

Returns:

true if the outputFormat may be collected immediately

Throws:

Exception - if the input format can't be set successfully

input

public boolean input(Instance instance)

Input an instance for filtering. Filter requires all training instances be read before producing output.

Overrides:

input in class Filter

Parameters:

instance - the input instance

Returns:

true if the filtered instance may now be collected with output().

Throws:

IllegalStateException - if no input structure has been defined

batchFinished

public boolean batchFinished()

Signify that this batch of input to the filter is finished. If the filter requires all instances prior to filtering, output() may now be called to retrieve the filtered instances.

Overrides:

batchFinished in class Filter

Returns:

true if there are instances pending output

Throws:

IllegalStateException - if no input structure has been defined

getRevision

public String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Overrides:

getRevision in class Filter

Returns:

the revision

main

public static void main(String[] argv)

Main method for testing this class.

Parameters:

argv - should contain arguments to the filter: use -h for help