weka.filters
Class NominalToBinaryFilter

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

All Implemented Interfaces:

OptionHandler, java.io.Serializable

public class NominalToBinaryFilter

extends Filter

implements OptionHandler

Converts all nominal attributes into binary numeric attributes. An attribute with k values is transformed into k-1 new binary attributes (in a similar manner to CART if a numeric class is assigned). Currently requires that a class attribute be set (but this should be changed).

Valid filter-specific options are:

-N
If binary attributes are to be coded as nominal ones.

Author:

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

See Also:

Serialized Form

Fields inherited from class weka.filters.Filter

m_NewBatch

Constructor Summary

NominalToBinaryFilter()

Method Summary

boolean	batchFinished() Signify that this batch of input to the filter is finished.
boolean	getBinaryAttributesNominal() Gets if binary attributes are to be treated as nominal ones.
java.lang.String[]	getOptions() Gets the current settings of the filter.
boolean	input(Instance instance) Input an instance for filtering.
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	setBinaryAttributesNominal(boolean bool) Sets if binary attributes are to be treates as nominal ones.
boolean	setInputFormat(Instances instanceInfo) Sets the format of the input instances.
void	setOptions(java.lang.String[] options) Parses the options for this object.

Methods inherited from class weka.filters.Filter

batchFilterFile, 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

Constructor Detail

NominalToBinaryFilter

public NominalToBinaryFilter()

Method Detail

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

Throws:

java.lang.Exception - if the input format can't be set successfully

input

public boolean input(Instance instance)

Input an instance for filtering. Filter requires all training 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

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.

Overrides:

batchFinished in class Filter

Returns:

true if there are instances pending output

Throws:

java.lang.IllegalStateException - if no input structure has been defined

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 the options for this object. Valid options are:

-N
If binary attributes are to be coded as nominal ones.

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

getBinaryAttributesNominal

public boolean getBinaryAttributesNominal()

Gets if binary attributes are to be treated as nominal ones.

Returns:

true if binary attributes are to be treated as nominal ones

setBinaryAttributesNominal

public void setBinaryAttributesNominal(boolean bool)

Sets if binary attributes are to be treates as nominal ones.

Parameters:

bool - true if binary attributes are to be treated as nominal ones

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