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Class weka.filters.FirstOrderFilter
java.lang.Object
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+----weka.filters.Filter
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+----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)
FirstOrderFilter()
-
attributeIndicesTipText()
- Returns the tip text for this property
getAttributeIndices()
- Get the current range selection
getOptions()
- Gets the current settings of the filter.
input(Instance)
- Input an instance for filtering.
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)
setInputFormat(Instances)
- Sets the format of the input instances.
setOptions(String[])
- Parses a given list of options controlling the behaviour of this object.
FirstOrderFilter
public FirstOrderFilter()
listOptions
public java.util.Enumeration listOptions()
Returns an enumeration describing the available options
- 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)
- 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.
- 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.
- 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
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
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
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