weka.filters
Class InstanceFilter

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

All Implemented Interfaces:

OptionHandler, java.io.Serializable

public class InstanceFilter

extends Filter

implements OptionHandler

Filters instances according to the value of an attribute.

Valid filter-specific options are:

-C num
Choose attribute to be used for selection (default last).

-S num
Numeric value to be used for selection on numeric attribute. Instances with values smaller than given value will be selected. (default 0)

-L index1,index2-index4,...
Range of label indices to be used for selection on nominal attribute. First and last are valid indexes. (default all values)

-M
Missing values count as a match. This setting is independent of the -V option. (default missing values don't match)

-V
Invert matching sense.

-H
When selecting on nominal attributes, removes header references to excluded values.

Author:

Eibe Frank (eibe@cs.waikato.ac.nz)

See Also:

Serialized Form

Field Summary

protected int	m_Attribute Stores which attribute to be used for filtering
protected int	m_AttributeSet Stores the attribute setting
protected boolean	m_Inverse Inverse of test to be used?
protected boolean	m_MatchMissingValues True if missing values should count as a match
protected boolean	m_ModifyHeader Modify header for nominal attributes?
protected int[]	m_NominalMapping If m_ModifyHeader, stores a mapping from old to new indexes
protected double	m_Value Stores which value of a numeric attribute is to be used for filtering.
protected Range	m_Values Stores which values of nominal attribute are to be used for filtering.

Fields inherited from class weka.filters.Filter

m_NewBatch

Constructor Summary

InstanceFilter()
Default constructor

Method Summary

int	getAttributeIndex() Get the attribute to be used for selection (-1 for last)
boolean	getInvertSelection() Get whether the supplied columns are to be removed or kept
boolean	getMatchMissingValues() Gets whether missing values are counted as a match.
boolean	getModifyHeader() Gets whether the header will be modified when selecting on nominal attributes.
java.lang.String	getNominalIndices() Get the set of nominal value indices that will be used for selection
java.lang.String[]	getOptions() Gets the current settings of the filter.
double	getSplitPoint() Get the split point used for numeric selection
boolean	input(Instance instance) Input an instance for filtering.
boolean	isNominal() Returns true if selection attribute is nominal.
boolean	isNumeric() Returns true if selection attribute is numeric.
java.util.Enumeration	listOptions() Returns an enumeration describing the available options
static void	main(java.lang.String[] argv) Main method for testing this class.
void	setAttributeIndex(int attribute) Sets attribute to be used for selection
boolean	setInputFormat(Instances instanceInfo) Sets the format of the input instances.
void	setInvertSelection(boolean invert) Set whether selected values should be removed or kept.
void	setMatchMissingValues(boolean newMatchMissingValues) Sets whether missing values are counted as a match.
void	setModifyHeader(boolean newModifyHeader) Sets whether the header will be modified when selecting on nominal attributes.
void	setNominalIndices(java.lang.String rangeList) Set which nominal labels are to be included in the selection.
void	setNominalIndicesArr(int[] values) Set which values of a nominal attribute are to be used for selection.
void	setOptions(java.lang.String[] options) Parses a given list of options.
void	setSplitPoint(double value) Split point to be used for selection on numeric attribute.

Methods inherited from class weka.filters.Filter

batchFilterFile, batchFinished, bufferInput, copyStringValues, copyStringValues, filterFile, flushInput, getInputFormat, getInputStringIndex, getOutputFormat, getOutputStringIndex, getStringIndices, 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_AttributeSet

protected int m_AttributeSet

Stores the attribute setting

m_Attribute

protected int m_Attribute

Stores which attribute to be used for filtering

m_Values

protected Range m_Values

Stores which values of nominal attribute are to be used for filtering.

m_Value

protected double m_Value

Stores which value of a numeric attribute is to be used for filtering.

m_Inverse

protected boolean m_Inverse

Inverse of test to be used?

m_MatchMissingValues

protected boolean m_MatchMissingValues

True if missing values should count as a match

m_ModifyHeader

protected boolean m_ModifyHeader

Modify header for nominal attributes?

m_NominalMapping

protected int[] m_NominalMapping

If m_ModifyHeader, stores a mapping from old to new indexes

Constructor Detail

InstanceFilter

public InstanceFilter()

Default constructor

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 given list of options. Valid options are:

-C num
Choose attribute to be used for selection (default last).

-S num
Numeric value to be used for selection on numeric attribute. Instances with values smaller than given value will be selected. (default 0)

-L index1,index2-index4,...
Range of label indices to be used for selection on nominal attribute. First and last are valid indexes. (default all values)

-M
Missing values count as a match. This setting is independent of the -V option. (default missing values don't match)

-V
Invert matching sense.

-H
When selecting on nominal attributes, removes header references to excluded values.

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

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).

Throws:

UnsupportedAttributeTypeException - if the specified attribute is neither numeric or nominal.

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:

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

isNominal

public boolean isNominal()

Returns true if selection attribute is nominal.

Returns:

true if selection attribute is nominal

isNumeric

public boolean isNumeric()

Returns true if selection attribute is numeric.

Returns:

true if selection attribute is numeric

getModifyHeader

public boolean getModifyHeader()

Gets whether the header will be modified when selecting on nominal attributes.

Returns:

true if so.

setModifyHeader

public void setModifyHeader(boolean newModifyHeader)

Sets whether the header will be modified when selecting on nominal attributes.

Parameters:

newModifyHeader - true if so.

getAttributeIndex

public int getAttributeIndex()

Get the attribute to be used for selection (-1 for last)

Returns:

the attribute index

setAttributeIndex

public void setAttributeIndex(int attribute)

Sets attribute to be used for selection

Parameters:

attribute - the attribute's index (-1 for last);

getSplitPoint

public double getSplitPoint()

Get the split point used for numeric selection

Returns:

the numeric split point

setSplitPoint

public void setSplitPoint(double value)

Split point to be used for selection on numeric attribute.

Parameters:

value - the split point

getMatchMissingValues

public boolean getMatchMissingValues()

Gets whether missing values are counted as a match.

Returns:

true if missing values are counted as a match.

setMatchMissingValues

public void setMatchMissingValues(boolean newMatchMissingValues)

Sets whether missing values are counted as a match.

Parameters:

newMatchMissingValues - true if missing values are counted as a match.

getInvertSelection

public boolean getInvertSelection()

Get 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)

Set whether selected values should be removed or kept. If true the selected values are kept and unselected values are deleted.

Parameters:

invert - the new invert setting

getNominalIndices

public java.lang.String getNominalIndices()

Get the set of nominal value indices that will be used for selection

Returns:

rangeList a string representing the list of nominal indices.

setNominalIndices

public void setNominalIndices(java.lang.String rangeList)

Set which nominal labels are to be included in the selection.

Parameters:

rangeList - a string representing the list of nominal indices. eg: first-3,5,6-last

Throws:

InvalidArgumentException - if an invalid range list is supplied

setNominalIndicesArr

public void setNominalIndicesArr(int[] values)

Set which values of a nominal attribute are to be used for selection.

Parameters:

values - an array containing indexes of values to be used for selection

Throws:

InvalidArgumentException - if an invalid set of ranges is supplied

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