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Class weka.filters.AttributeFilter

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

public class AttributeFilter

extends Filter

implements OptionHandler

Valid filter-specific options are:

-R index1,index2-index4,...
Specify list of columns to delete. First and last are valid indexes. (default none)

-V
Invert matching sense (i.e. only keep specified columns)

Version:

$Revision: 1.3 $

Author:

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

AttributeFilter()

getAttributeIndices()

Get the current range selection.

getInvertSelection()

Get whether the supplied columns are to be removed or kept

getOptions()

Gets the current settings of the filter.

input(Instance)

Input an instance for filtering.

inputFormat(Instances)

Sets the format of the input instances.

listOptions()

Returns an enumeration describing the available options

main(String[])

Main method for testing this class.

setAttributeIndices(String)

Set which attributes are to be deleted (or kept if invert is true)

setAttributeIndicesArray(int[])

Set which attributes are to be deleted (or kept if invert is true)

setInvertSelection(boolean)

Set whether selected columns should be removed or kept.

setOptions(String[])

Parses a given list of options controlling the behaviour of this object.

 public AttributeFilter()

 public Enumeration listOptions()

Returns an enumeration describing the available options

Returns:

an enumeration of all the available options

 public void setOptions(String options[]) throws Exception

Parses a given list of options controlling the behaviour of this object. Valid options are:

-R index1,index2-index4,...
Specify list of columns to delete. First and last are valid indexes. (default none)

-V
Invert matching sense (i.e. only keep specified columns)

Parameters:

options - the list of options as an array of strings

Throws: Exception

if an option is not supported

 public String[] getOptions()

Gets the current settings of the filter.

Returns:

an array of strings suitable for passing to setOptions

 public boolean inputFormat(Instances instanceInfo) throws Exception

Sets the format of the input instances.

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 format couldn't be set successfully

Overrides:

inputFormat in class Filter

 public boolean input(Instance instance) throws Exception

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.

Parameters:

instance - the input instance

Returns:

true if the filtered instance may now be collected with output().

Throws: Exception

if the input instance was not of the correct format or if there was a problem with the filtering.

Overrides:

input in class Filter

 public boolean getInvertSelection()

Get whether the supplied columns are to be removed or kept

Returns:

true if the supplied columns will be kept

 public void setInvertSelection(boolean invert)

Set 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

 public String getAttributeIndices()

Get the current range selection.

Returns:

a string containing a comma separated list of ranges

 public void setAttributeIndices(String rangeList) throws Exception

Set which attributes are to be deleted (or kept if invert is true)

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: Exception

if an invalid range list is supplied

 public void setAttributeIndicesArray(int attributes[]) throws Exception

Set which attributes are to be deleted (or kept if invert is true)

Parameters:

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

Throws: Exception

if an invalid set of ranges is supplied

 public static void main(String argv[])

Main method for testing this class.

Parameters:

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

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