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Class weka.filters.FirstOrderFilter

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

public class FirstOrderFilter
extends Filter
implements 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: 1.13 $
Author:
Len Trigg (trigg@cs.waikato.ac.nz)

Constructor Index

 o FirstOrderFilter()
 

Method Index

 o attributeIndicesTipText()
Returns the tip text for this property
 o getAttributeIndices()
Get the current range selection
 o getOptions()
Gets the current settings of the filter.
 o input(Instance)
Input an instance for filtering.
 o listOptions()
Returns an enumeration describing the available options
 o main(String[])
Main method for testing this class.
 o setAttributeIndices(String)
Set which attributes are to be deleted (or kept if invert is true)
 o setAttributeIndicesArray(int[])
Set which attributes are to be deleted (or kept if invert is true)
 o setInputFormat(Instances)
Sets the format of the input instances.
 o setOptions(String[])
Parses a given list of options controlling the behaviour of this object.

Constructor Detail

 o FirstOrderFilter
public FirstOrderFilter()

Method Detail

 o listOptions
public java.util.Enumeration listOptions()
          Returns an enumeration describing the available options
Returns:
an enumeration of all the available options
 o 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)

Parameters:
options - the list of options as an array of strings
Throws:
java.lang.Exception - if an option is not supported
 o getOptions
public java.lang.String[] getOptions()
          Gets the current settings of the filter.
Returns:
an array of strings suitable for passing to setOptions
 o setInputFormat
public boolean setInputFormat(Instances instanceInfo) throws java.lang.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:
UnsupportedAttributeTypeException - if any of the selected attributes are not numeric
java.lang.Exception - if only one attribute has been selected.
Overrides:
setInputFormat in class Filter
 o 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.
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.
Overrides:
input in class Filter
 o 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
 o getAttributeIndices
public java.lang.String getAttributeIndices()
          Get the current range selection
Returns:
a string containing a comma separated list of ranges
 o 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
 o 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
 o 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

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