weka.filters.unsupervised.attribute
Class DownSample

java.lang.Object
  weka.filters.Filter
      weka.filters.SimpleFilter
          weka.filters.SimpleStreamFilter
              weka.filters.unsupervised.attribute.DownSample

All Implemented Interfaces:

Serializable, weka.core.CapabilitiesHandler, weka.core.OptionHandler, weka.core.RevisionHandler, weka.filters.StreamableFilter, weka.filters.UnsupervisedFilter

public class DownSample
extends weka.filters.SimpleStreamFilter
implements weka.filters.UnsupervisedFilter

A simple filter that retains only every nth attribute.

Valid options are:

 -D
  Turns on output of debugging information.

 -nth <int>
  Only every n-th point will be output (>0).
  (default: 1)

Version:

$Revision: 4521 $

Author:

fracpete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Field Summary

protected int

m_NthPoint the nth point.

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

DownSample()

Method Summary

protected weka.core.Instances	determineOutputFormat(weka.core.Instances inputFormat) Determines the output format based on the input format and returns this.
weka.core.Capabilities	getCapabilities() Returns the Capabilities of this filter.
int	getNthPoint() Returns the nth point setting.
String[]	getOptions() Gets the current settings of the filter.
String	getRevision() Returns the revision string.
String	globalInfo() Returns a string describing this classifier.
Enumeration	listOptions() Returns an enumeration describing the available options.
static void	main(String[] args) Main method for testing this class.
String	nthPointTipText() Returns the tip text for this property.
protected weka.core.Instance	process(weka.core.Instance instance) processes the given instance (may change the provided instance) and returns the modified version.
void	setNthPoint(int value) Sets the nth point setting.
void	setOptions(String[] options) Parses a list of options for this object.

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, mayRemoveInstanceAfterFirstBatchDone, 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_NthPoint

protected int m_NthPoint

the nth point.

Constructor Detail

DownSample

public DownSample()

Method Detail

globalInfo

public String globalInfo()

Returns a string describing this classifier.

Specified by:

globalInfo in class weka.filters.SimpleFilter

Returns:

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

listOptions

public Enumeration listOptions()

Returns an enumeration describing the available options.

Specified by:

listOptions in interface weka.core.OptionHandler

Overrides:

listOptions in class weka.filters.SimpleFilter

Returns:

an enumeration of all the available options.

setOptions

public void setOptions(String[] options)
                throws Exception

Parses a list of options for this object. Also resets the state of the filter (this reset doesn't affect the options).

Specified by:

setOptions in interface weka.core.OptionHandler

Overrides:

setOptions in class weka.filters.SimpleFilter

Parameters:

options - the list of options as an array of strings

Throws:

Exception - if an option is not supported

See Also:

SimpleFilter.reset()

getOptions

public String[] getOptions()

Gets the current settings of the filter.

Specified by:

getOptions in interface weka.core.OptionHandler

Overrides:

getOptions in class weka.filters.SimpleFilter

Returns:

an array of strings suitable for passing to setOptions

setNthPoint

public void setNthPoint(int value)

Sets the nth point setting.

Parameters:

value - the nth point

getNthPoint

public int getNthPoint()

Returns the nth point setting.

Returns:

the nth point

nthPointTipText

public String nthPointTipText()

Returns the tip text for this property.

Returns:

tip text for this property suitable for displaying in the GUI or for listing the options.

getCapabilities

public weka.core.Capabilities getCapabilities()

Returns the Capabilities of this filter. Derived filters have to override this method to enable capabilities.

Specified by:

getCapabilities in interface weka.core.CapabilitiesHandler

Overrides:

getCapabilities in class weka.filters.Filter

Returns:

the capabilities of this object

See Also:

Capabilities

determineOutputFormat

protected weka.core.Instances determineOutputFormat(weka.core.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 weka.filters.SimpleStreamFilter

Parameters:

inputFormat - the input format to base the output format on

Returns:

the output format

Throws:

Exception - in case the determination goes wrong

process

protected weka.core.Instance process(weka.core.Instance instance)
                              throws Exception

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

Specified by:

process in class weka.filters.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 weka.core.RevisionHandler

Overrides:

getRevision in class weka.filters.Filter

Returns:

the revision

main

public static void main(String[] args)

Main method for testing this class.

Parameters:

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