weka.filters
Class RandomizeFilter

java.lang.Object
  |
  +--weka.filters.Filter
        |
        +--weka.filters.RandomizeFilter

All Implemented Interfaces:

OptionHandler, java.io.Serializable

public class RandomizeFilter

extends Filter

implements OptionHandler

This filter randomly shuffles the order of instances passed through it. The random number generator is reset with the seed value whenever setInputFormat() is called.

Valid filter-specific options are:

-S num
Specify the random number seed (default 42).

Author:

Len Trigg (trigg@cs.waikato.ac.nz)

See Also:

Serialized Form

Field Summary

protected java.util.Random	m_Random The current random number generator
protected int	m_Seed The random number seed

Fields inherited from class weka.filters.Filter

m_NewBatch

Constructor Summary

RandomizeFilter()

Method Summary

boolean	batchFinished() Signify that this batch of input to the filter is finished.
java.lang.String[]	getOptions() Gets the current settings of the filter.
int	getRandomSeed() Get the random number generator seed value.
java.util.Enumeration	listOptions() Returns an enumeration describing the available options
static void	main(java.lang.String[] argv) Main method for testing this class.
boolean	setInputFormat(Instances instanceInfo) Sets the format of the input instances.
void	setOptions(java.lang.String[] options) Parses a list of options for this object.
void	setRandomSeed(int newRandomSeed) Set the random number generator seed value.

Methods inherited from class weka.filters.Filter

batchFilterFile, bufferInput, copyStringValues, copyStringValues, filterFile, flushInput, getInputFormat, getInputStringIndex, getOutputFormat, getOutputStringIndex, getStringIndices, input, inputFormat, isOutputFormatDefined, numPendingOutput, output, outputFormat, outputFormatPeek, outputPeek, push, resetQueue, setOutputFormat, useFilter

Methods inherited from class java.lang.Object

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

Field Detail

m_Seed

protected int m_Seed

The random number seed

m_Random

protected java.util.Random m_Random

The current random number generator

Constructor Detail

RandomizeFilter

public RandomizeFilter()

Method Detail

listOptions

public java.util.Enumeration 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(java.lang.String[] options)
                throws java.lang.Exception

Parses a list of options for this object. Valid options are:

-S num
Specify the random number seed (default 42).

Specified by:

setOptions in interface OptionHandler

Parameters:

options - the list of options as an array of strings

Throws:

java.lang.Exception - if an option is not supported

getOptions

public java.lang.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

getRandomSeed

public int getRandomSeed()

Get the random number generator seed value.

Returns:

random number generator seed value.

setRandomSeed

public void setRandomSeed(int newRandomSeed)

Set the random number generator seed value.

Parameters:

newRandomSeed - value to use as the random number generator seed.

setInputFormat

public boolean setInputFormat(Instances instanceInfo)
                       throws java.lang.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

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. Any subsequent instances filtered should be filtered based on setting obtained from the first batch (unless the setInputFormat has been re-assigned or new options have been set). This implementation randomizes all the instances received in the batch.

Overrides:

batchFinished in class Filter

Returns:

true if there are instances pending output

Throws:

java.lang.IllegalStateException - if no input format has been set.

main

public static void main(java.lang.String[] argv)

Main method for testing this class.

Parameters:

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