weka.filters.unsupervised.attribute
Class FirstOrder

java.lang.Object
  |
  +--weka.filters.Filter
        |
        +--weka.filters.unsupervised.attribute.FirstOrder

All Implemented Interfaces:

OptionHandler, java.io.Serializable, StreamableFilter, UnsupervisedFilter

public class FirstOrder

extends Filter

implements UnsupervisedFilter, StreamableFilter, OptionHandler

This instance filter takes a range of N numeric attributes and replaces them with N-1 numeric attributes, the values of which are the difference between consecutive attribute values from the original instance. eg:

Original attribute values
0.1, 0.2, 0.3, 0.1, 0.3

New attribute values
0.1, 0.1, 0.1, -0.2, -0.2

The range of attributes used is taken in numeric order. That is, a range spec of 7-11,3-5 will use the attribute ordering 3,4,5,7,8,9,10,11 for the differences, not 7,8,9,10,11,3,4,5.

Valid filter-specific options are:

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

Version:

$Revision: 1.2 $

Author:

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

See Also:

Serialized Form

Constructor Summary

FirstOrder()

Method Summary

java.lang.String	attributeIndicesTipText() Returns the tip text for this property
java.lang.String	getAttributeIndices() Get the current range selection
java.lang.String[]	getOptions() Gets the current settings of the filter.
java.lang.String	globalInfo() Returns a string describing this 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	setAttributeIndices(java.lang.String rangeList) Set which attributes are to be deleted (or kept if invert is true)
void	setAttributeIndicesArray(int[] attributes) Set which attributes are to be deleted (or kept if invert is true)
boolean	setInputFormat(Instances instanceInfo) Sets the format of the input instances.
void	setOptions(java.lang.String[] options) Parses a given list of options controlling the behaviour of this object.

Methods inherited from class weka.filters.Filter

batchFilterFile, batchFinished, filterFile, getOutputFormat, inputFormat, isOutputFormatDefined, numPendingOutput, output, outputFormat, outputPeek, useFilter

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FirstOrder

public FirstOrder()

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing this filter

Returns:

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

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 controlling the behaviour of this object. Valid options are:

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

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).

Returns:

true if the outputFormat may be collected immediately

Throws:

UnsupportedAttributeTypeException - if any of the selected attributes are not numeric

java.lang.Exception - if only one attribute has been selected.

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 defined.

attributeIndicesTipText

public java.lang.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 java.lang.String getAttributeIndices()

Get the current range selection

Returns:

a string containing a comma separated list of ranges

setAttributeIndices

public void setAttributeIndices(java.lang.String rangeList)
                         throws java.lang.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:

java.lang.Exception - if an invalid range list is supplied

setAttributeIndicesArray

public void setAttributeIndicesArray(int[] attributes)
                              throws java.lang.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:

java.lang.Exception - 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