weka.filters.unsupervised.attribute

Class RandomSubset

java.lang.Object

weka.filters.Filter

weka.filters.SimpleFilter

weka.filters.SimpleStreamFilter

weka.filters.unsupervised.attribute.RandomSubset

All Implemented Interfaces:

Serializable, CapabilitiesHandler, OptionHandler, RevisionHandler, StreamableFilter

public class RandomSubset
extends SimpleStreamFilter

Chooses a random subset of attributes, either an absolute number or a percentage. The class is always included in the output (as the last attribute).

Valid options are:

 -D
  Turns on output of debugging information.

 -N <double>
  The number of attributes to randomly select.
  If < 1 then percentage, >= 1 absolute number.
  (default: 0.5)

 -S <int>
  The seed value.
  (default: 1)

Version:

$Revision: 5547 $

Author:

fracpete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	m_Indices The indices of the attributes that got selected.
protected double	m_NumAttributes The number of attributes to randomly choose (>= 1 absolute number of attributes, < 1 percentage).
protected int	m_Seed The seed value.

Fields inherited from class weka.filters.SimpleFilter

m_Debug

Fields inherited from class weka.filters.Filter

m_FirstBatchDone, m_InputRelAtts, m_InputStringAtts, m_NewBatch, m_OutputRelAtts, m_OutputStringAtts

Constructor Summary

Constructors

Constructor and Description
RandomSubset()

Method Summary

Modifier and Type	Method and Description
protected Instances	determineOutputFormat(Instances inputFormat) Determines the output format based on the input format and returns this.
Capabilities	getCapabilities() Returns the Capabilities of this filter.
double	getNumAttributes() Get the number of attributes (< 1 percentage, >= 1 absolute number).
String[]	getOptions() Gets the current settings of the filter.
String	getRevision() Returns the revision string.
int	getSeed() Get the seed value for the random number generator.
String	globalInfo() Returns a string describing this filter.
Enumeration	listOptions() Returns an enumeration describing the available options.
static void	main(String[] args) Runs the filter with the given parameters.
String	numAttributesTipText() Returns the tip text for this property.
protected Instance	process(Instance instance) processes the given instance (may change the provided instance) and returns the modified version.
String	seedTipText() Returns the tip text for this property.
void	setNumAttributes(double value) Set the number of attributes.
void	setOptions(String[] options) Parses a given list of options.
void	setSeed(int value) Set the seed value for the random number generator.

Methods inherited from class weka.filters.SimpleStreamFilter

batchFinished, hasImmediateOutputFormat, input, preprocess, process

Methods inherited from class weka.filters.SimpleFilter

debugTipText, getDebug, reset, setDebug, setInputFormat

Methods inherited from class weka.filters.Filter

batchFilterFile, bufferInput, copyValues, copyValues, filterFile, flushInput, getCapabilities, getInputFormat, getOutputFormat, initInputLocators, initOutputLocators, inputFormatPeek, isFirstBatchDone, isNewBatch, isOutputFormatDefined, makeCopies, makeCopy, numPendingOutput, output, outputFormatPeek, outputPeek, push, resetQueue, runFilter, setOutputFormat, testInputFormat, toString, useFilter, wekaStaticWrapper

Methods inherited from class java.lang.Object

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

Field Detail

m_NumAttributes

protected double m_NumAttributes

The number of attributes to randomly choose (>= 1 absolute number of attributes, < 1 percentage).

m_Seed

protected int m_Seed

The seed value.

m_Indices

protected int[] m_Indices

The indices of the attributes that got selected.

Constructor Detail

RandomSubset

public RandomSubset()

Method Detail

globalInfo

public String globalInfo()

Returns a string describing this filter.

Specified by:

globalInfo in class SimpleFilter

Returns:

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

listOptions

public Enumeration listOptions()

Returns an enumeration describing the available options.

Specified by:

listOptions in interface OptionHandler

Overrides:

listOptions in class SimpleFilter

Returns:

an enumeration of all the available options.

getOptions

public String[] getOptions()

Gets the current settings of the filter.

Specified by:

getOptions in interface OptionHandler

Overrides:

getOptions in class SimpleFilter

Returns:

an array of strings suitable for passing to setOptions

setOptions

public void setOptions(String[] options)
                throws Exception

Parses a given list of options.

Valid options are:

 -D
  Turns on output of debugging information.

 -N <double>
  The number of attributes to randomly select.
  If < 1 then percentage, >= 1 absolute number.
  (default: 0.5)

 -S <int>
  The seed value.
  (default: 1)

Specified by:

setOptions in interface OptionHandler

Overrides:

setOptions in class SimpleFilter

Parameters:

options - the list of options as an array of strings

Throws:

Exception - if an option is not supported

See Also:

SimpleFilter.reset()

numAttributesTipText

public String numAttributesTipText()

Returns the tip text for this property.

Returns:

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

getNumAttributes

public double getNumAttributes()

Get the number of attributes (< 1 percentage, >= 1 absolute number).

Returns:

the number of attributes.

setNumAttributes

public void setNumAttributes(double value)

Set the number of attributes.

Parameters:

value - the number of attributes to use.

seedTipText

public String seedTipText()

Returns the tip text for this property.

Returns:

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

getSeed

public int getSeed()

Get the seed value for the random number generator.

Returns:

the seed value.

setSeed

public void setSeed(int value)

Set the seed value for the random number generator.

Parameters:

value - the seed value.

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

determineOutputFormat

protected Instances determineOutputFormat(Instances inputFormat)
                                   throws Exception

Determines the output format based on the input format and returns this. In case the output format cannot be returned immediately, i.e., hasImmediateOutputFormat() returns false, then this method will called from batchFinished() after the call of preprocess(Instances), in which, e.g., statistics for the actual processing step can be gathered.

Specified by:

determineOutputFormat in class SimpleStreamFilter

Parameters:

inputFormat - the input format to base the output format on

Returns:

the output format

Throws:

Exception - in case the determination goes wrong

See Also:

SimpleStreamFilter.hasImmediateOutputFormat(), SimpleStreamFilter.batchFinished(), SimpleStreamFilter.preprocess(Instances)

process

protected Instance process(Instance instance)
                    throws Exception

processes the given instance (may change the provided instance) and returns the modified version.

Specified by:

process in class SimpleStreamFilter

Parameters:

instance - the instance to process

Returns:

the modified data

Throws:

Exception - in case the processing goes wrong

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[] args)

Runs the filter with the given parameters. Use -h to list options.

Parameters:

args - the commandline options