weka.filters.supervised.attribute

Class Discretize

java.lang.Object

weka.filters.Filter

weka.filters.supervised.attribute.Discretize

All Implemented Interfaces:

Serializable, CapabilitiesHandler, OptionHandler, RevisionHandler, TechnicalInformationHandler, WeightedInstancesHandler, SupervisedFilter

public class Discretize
extends Filter
implements SupervisedFilter, OptionHandler, WeightedInstancesHandler, TechnicalInformationHandler

An instance filter that discretizes a range of numeric attributes in the dataset into nominal attributes. Discretization is by Fayyad & Irani's MDL method (the default).

For more information, see:

Usama M. Fayyad, Keki B. Irani: Multi-interval discretization of continuousvalued attributes for classification learning. In: Thirteenth International Joint Conference on Articial Intelligence, 1022-1027, 1993.

Igor Kononenko: On Biases in Estimating Multi-Valued Attributes. In: 14th International Joint Conference on Articial Intelligence, 1034-1040, 1995.

BibTeX:

 @inproceedings{Fayyad1993,
    author = {Usama M. Fayyad and Keki B. Irani},
    booktitle = {Thirteenth International Joint Conference on Articial Intelligence},
    pages = {1022-1027},
    publisher = {Morgan Kaufmann Publishers},
    title = {Multi-interval discretization of continuousvalued attributes for classification learning},
    volume = {2},
    year = {1993}
 }
 
 @inproceedings{Kononenko1995,
    author = {Igor Kononenko},
    booktitle = {14th International Joint Conference on Articial Intelligence},
    pages = {1034-1040},
    title = {On Biases in Estimating Multi-Valued Attributes},
    year = {1995},
    PS = {http://ai.fri.uni-lj.si/papers/kononenko95-ijcai.ps.gz}
 }
 

Valid options are:

 -R <col1,col2-col4,...>
  Specifies list of columns to Discretize. First and last are valid indexes.
  (default none)

 -V
  Invert matching sense of column indexes.

 -D
  Output binary attributes for discretized attributes.

 -Y
  Use bin numbers rather than ranges for discretized attributes.

 -E
  Use better encoding of split point for MDL.

 -K
  Use Kononenko's MDL criterion.

 -precision <integer>
  Precision for bin boundary labels.
  (default = 6 decimal places).

Version:

$Revision: 10231 $

Author:

Len Trigg (trigg@cs.waikato.ac.nz), Eibe Frank (eibe@cs.waikato.ac.nz)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Discretize() Constructor - initialises the filter

Method Summary

Methods

Modifier and Type	Method and Description
String	attributeIndicesTipText() Returns the tip text for this property
boolean	batchFinished() Signifies that this batch of input to the filter is finished.
String	binRangePrecisionTipText() Returns the tip text for this property
String	getAttributeIndices() Gets the current range selection
int	getBinRangePrecision() Get the precision for bin boundaries.
String	getBinRangesString(int attributeIndex) Gets the bin ranges string for an attribute
Capabilities	getCapabilities() Returns the Capabilities of this filter.
double[]	getCutPoints(int attributeIndex) Gets the cut points for an attribute
boolean	getInvertSelection() Gets whether the supplied columns are to be removed or kept
boolean	getMakeBinary() Gets whether binary attributes should be made for discretized ones.
String[]	getOptions() Gets the current settings of the filter.
String	getRevision() Returns the revision string.
TechnicalInformation	getTechnicalInformation() Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
boolean	getUseBetterEncoding() Gets whether better encoding is to be used for MDL.
boolean	getUseBinNumbers() Gets whether bin numbers rather than ranges should be used for discretized attributes.
boolean	getUseKononenko() Gets whether Kononenko's MDL criterion is to be used.
String	globalInfo() Returns a string describing this filter
boolean	input(Instance instance) Input an instance for filtering.
String	invertSelectionTipText() Returns the tip text for this property
Enumeration<Option>	listOptions() Gets an enumeration describing the available options.
static void	main(String[] argv) Main method for testing this class.
String	makeBinaryTipText() Returns the tip text for this property
void	setAttributeIndices(String rangeList) Sets which attributes are to be Discretized (only numeric attributes among the selection will be Discretized).
void	setAttributeIndicesArray(int[] attributes) Sets which attributes are to be Discretized (only numeric attributes among the selection will be Discretized).
void	setBinRangePrecision(int p) Set the precision for bin boundaries.
boolean	setInputFormat(Instances instanceInfo) Sets the format of the input instances.
void	setInvertSelection(boolean invert) Sets whether selected columns should be removed or kept.
void	setMakeBinary(boolean makeBinary) Sets whether binary attributes should be made for discretized ones.
void	setOptions(String[] options) Parses a given list of options.
void	setUseBetterEncoding(boolean useBetterEncoding) Sets whether better encoding is to be used for MDL.
void	setUseBinNumbers(boolean useBinNumbers) Sets whether bin numbers rather than ranges should be used for discretized attributes.
void	setUseKononenko(boolean useKon) Sets whether Kononenko's MDL criterion is to be used.
String	useBetterEncodingTipText() Returns the tip text for this property
String	useBinNumbersTipText() Returns the tip text for this property
String	useKononenkoTipText() Returns the tip text for this property

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

Discretize

public Discretize()

Constructor - initialises the filter

Method Detail

listOptions

public Enumeration<Option> listOptions()

Gets 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:

 -R <col1,col2-col4,...>
  Specifies list of columns to Discretize. First and last are valid indexes.
  (default none)

 -V
  Invert matching sense of column indexes.

 -D
  Output binary attributes for discretized attributes.

 -Y
  Use bin numbers rather than ranges for discretized attributes.

 -E
  Use better encoding of split point for MDL.

 -K
  Use Kononenko's MDL criterion.

 -precision <integer>
  Precision for bin boundary labels.
  (default = 6 decimal places).

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

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. Ordinarily the instance is processed and made available for output immediately. Some filters require all 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 format has been defined.

batchFinished

public boolean batchFinished()

Signifies 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

globalInfo

public String globalInfo()

Returns a string describing this filter

Returns:

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

getTechnicalInformation

public TechnicalInformation getTechnicalInformation()

Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.

Specified by:

getTechnicalInformation in interface TechnicalInformationHandler

Returns:

the technical information about this class

binRangePrecisionTipText

public String binRangePrecisionTipText()

Returns the tip text for this property

Returns:

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

setBinRangePrecision

public void setBinRangePrecision(int p)

Set the precision for bin boundaries. Only affects the boundary values used in the labels for the converted attributes; internal cutpoints are at full double precision.

Parameters:

p - the precision for bin boundaries

getBinRangePrecision

public int getBinRangePrecision()

Get the precision for bin boundaries. Only affects the boundary values used in the labels for the converted attributes; internal cutpoints are at full double precision.

Returns:

the precision for bin boundaries

makeBinaryTipText

public String makeBinaryTipText()

Returns the tip text for this property

Returns:

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

getMakeBinary

public boolean getMakeBinary()

Gets whether binary attributes should be made for discretized ones.

Returns:

true if attributes will be binarized

setMakeBinary

public void setMakeBinary(boolean makeBinary)

Sets whether binary attributes should be made for discretized ones.

Parameters:

makeBinary - if binary attributes are to be made

useBinNumbersTipText

public String useBinNumbersTipText()

Returns the tip text for this property

Returns:

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

getUseBinNumbers

public boolean getUseBinNumbers()

Gets whether bin numbers rather than ranges should be used for discretized attributes.

Returns:

true if bin numbers should be used

setUseBinNumbers

public void setUseBinNumbers(boolean useBinNumbers)

Sets whether bin numbers rather than ranges should be used for discretized attributes.

Parameters:

useBinNumbers - if bin numbers should be used

useKononenkoTipText

public String useKononenkoTipText()

Returns the tip text for this property

Returns:

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

getUseKononenko

public boolean getUseKononenko()

Gets whether Kononenko's MDL criterion is to be used.

Returns:

true if Kononenko's criterion will be used.

setUseKononenko

public void setUseKononenko(boolean useKon)

Sets whether Kononenko's MDL criterion is to be used.

Parameters:

useKon - true if Kononenko's one is to be used

useBetterEncodingTipText

public String useBetterEncodingTipText()

Returns the tip text for this property

Returns:

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

getUseBetterEncoding

public boolean getUseBetterEncoding()

Gets whether better encoding is to be used for MDL.

Returns:

true if the better MDL encoding will be used

setUseBetterEncoding

public void setUseBetterEncoding(boolean useBetterEncoding)

Sets whether better encoding is to be used for MDL.

Parameters:

useBetterEncoding - true if better encoding to be used.

invertSelectionTipText

public String invertSelectionTipText()

Returns the tip text for this property

Returns:

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

getInvertSelection

public boolean getInvertSelection()

Gets whether the supplied columns are to be removed or kept

Returns:

true if the supplied columns will be kept

setInvertSelection

public void setInvertSelection(boolean invert)

Sets whether selected columns should be removed or kept. If true the selected columns are kept and unselected columns are deleted. If false selected columns are deleted and unselected columns are kept.

Parameters:

invert - the new invert setting

attributeIndicesTipText

public String attributeIndicesTipText()

Returns the tip text for this property

Returns:

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

getAttributeIndices

public String getAttributeIndices()

Gets the current range selection

Returns:

a string containing a comma separated list of ranges

setAttributeIndices

public void setAttributeIndices(String rangeList)

Sets which attributes are to be Discretized (only numeric attributes among the selection will be Discretized).

Parameters:

rangeList - a string representing the list of attributes. Since the string will typically come from a user, attributes are indexed from 1.
eg: first-3,5,6-last

Throws:

IllegalArgumentException - if an invalid range list is supplied

setAttributeIndicesArray

public void setAttributeIndicesArray(int[] attributes)

Sets which attributes are to be Discretized (only numeric attributes among the selection will be Discretized).

Parameters:

attributes - an array containing indexes of attributes to Discretize. Since the array will typically come from a program, attributes are indexed from 0.

Throws:

IllegalArgumentException - if an invalid set of ranges is supplied

getCutPoints

public double[] getCutPoints(int attributeIndex)

Gets the cut points for an attribute

Parameters:

attributeIndex - the index (from 0) of the attribute to get the cut points of

Returns:

an array containing the cutpoints (or null if the attribute requested isn't being Discretized

getBinRangesString

public String getBinRangesString(int attributeIndex)

Gets the bin ranges string for an attribute

Parameters:

attributeIndex - the index (from 0) of the attribute to get the bin ranges string of

Returns:

the bin ranges string (or null if the attribute requested has been discretized into only one interval.)

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