weka.filters.unsupervised.attribute

Class MathExpression

java.lang.Object

weka.filters.Filter

weka.filters.unsupervised.attribute.PotentialClassIgnorer

weka.filters.unsupervised.attribute.MathExpression

All Implemented Interfaces:

java.io.Serializable, CapabilitiesHandler, CapabilitiesIgnorer, CommandlineRunnable, OptionHandler, RevisionHandler, WeightedAttributesHandler, WeightedInstancesHandler, UnsupervisedFilter

public class MathExpression
extends PotentialClassIgnorer
implements UnsupervisedFilter, WeightedInstancesHandler, WeightedAttributesHandler

Modify numeric attributes according to a given mathematical expression. Supported operators are +, -, *, /, pow, log, abs, cos, exp, sqrt, tan, sin, ceil, floor, rint, (, ), MEAN, MAX, MIN, SD, COUNT, SUM, SUMSQUARED, ifelse. The 'A' letter refers to the value of the attribute being processed. Other attribute values (numeric only) can be accessed through the variables A1, A2, A3, ... Example: pow(A,6)/(MEAN+MAX)*ifelse(A<0,0,sqrt(A))+ifelse(![A>9 && A<15])

Valid options are:

 -unset-class-temporarily
  Unsets the class index temporarily before the filter is
  applied to the data.
  (default: no)
 

 -E <expression>
  Specify the expression to apply.
 

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

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

Version:

$Revision: 14534 $

Author:

Eibe Frank (eibe@cs.waikato.ac.nz), Prados Julien (julien.prados@cui.unige.ch)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	m_defaultExpression The default modification expression

Constructor Summary

Constructors

Constructor and Description
MathExpression() Constructor

Method Summary

Modifier and Type	Method and Description
boolean	batchFinished() Signify that this batch of input to the filter is finished.
java.lang.String	expressionTipText() Returns the tip text for this property
Capabilities	getCapabilities() Returns the Capabilities of this filter.
java.lang.String	getExpression() Get the expression
java.lang.String	getIgnoreRange() Get the current range selection.
boolean	getInvertSelection() Get whether the supplied columns are to be select or unselect
java.lang.String[]	getOptions() Gets the current settings of the filter.
java.lang.String	getRevision() Returns the revision string.
java.lang.String	globalInfo() Returns a string describing this filter
java.lang.String	ignoreRangeTipText() Returns the tip text for this property
boolean	input(Instance instance) Input an instance for filtering.
java.lang.String	invertSelectionTipText() Returns the tip text for this property
java.util.Enumeration<Option>	listOptions() Returns an enumeration describing the available options.
static void	main(java.lang.String[] argv) Main method for testing this class.
void	setExpression(java.lang.String expr) Set the expression to apply
void	setIgnoreRange(java.lang.String rangeList) Set which attributes are to be ignored
boolean	setInputFormat(Instances instanceInfo) Sets the format of the input instances.
void	setInvertSelection(boolean invert) Set whether selected columns should be select or unselect.
void	setOptions(java.lang.String[] options) Parses a given list of options.

Methods inherited from class weka.filters.unsupervised.attribute.PotentialClassIgnorer

getIgnoreClass, getOutputFormat, ignoreClassTipText, setIgnoreClass

Methods inherited from class weka.filters.Filter

batchFilterFile, debugTipText, doNotCheckCapabilitiesTipText, filterFile, getCapabilities, getCopyOfInputFormat, getDebug, getDoNotCheckCapabilities, isFirstBatchDone, isNewBatch, isOutputFormatDefined, makeCopies, makeCopy, mayRemoveInstanceAfterFirstBatchDone, numPendingOutput, output, outputPeek, postExecution, preExecution, run, runFilter, setDebug, setDoNotCheckCapabilities, toString, useFilter, wekaStaticWrapper

Methods inherited from class java.lang.Object

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

Methods inherited from interface weka.core.OptionHandler

makeCopy

Field Detail

m_defaultExpression

public static final java.lang.String m_defaultExpression

The default modification expression

See Also:

Constant Field Values

Constructor Detail

MathExpression

public MathExpression()

Constructor

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

getCapabilities

public Capabilities getCapabilities()

Returns the Capabilities of this filter.

Specified by:

getCapabilities in interface CapabilitiesHandler

Overrides:

getCapabilities in class Filter

Returns:

the capabilities of this object

See Also:

Capabilities

setInputFormat

public boolean setInputFormat(Instances instanceInfo)
                       throws java.lang.Exception

Sets the format of the input instances.

Overrides:

setInputFormat in class PotentialClassIgnorer

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)
              throws java.lang.Exception

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.

java.lang.NullPointerException - if the input format has not been defined.

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

batchFinished

public boolean batchFinished()
                      throws java.lang.Exception

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

java.lang.NullPointerException - if no input structure has been defined,

java.lang.Exception - if there was a problem finishing the batch.

setOptions

public void setOptions(java.lang.String[] options)
                throws java.lang.Exception

Parses a given list of options.

Valid options are:

 -unset-class-temporarily
  Unsets the class index temporarily before the filter is
  applied to the data.
  (default: no)
 

 -E <expression>
  Specify the expression to apply.
 

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

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

Specified by:

setOptions in interface OptionHandler

Overrides:

setOptions in class PotentialClassIgnorer

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

Overrides:

getOptions in class PotentialClassIgnorer

Returns:

an array of strings suitable for passing to setOptions

listOptions

public java.util.Enumeration<Option> listOptions()

Returns an enumeration describing the available options.

Specified by:

listOptions in interface OptionHandler

Overrides:

listOptions in class PotentialClassIgnorer

Returns:

an enumeration of all the available options.

expressionTipText

public java.lang.String expressionTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

setExpression

public void setExpression(java.lang.String expr)
                   throws java.lang.Exception

Set the expression to apply

Parameters:

expr - a mathematical expression to apply

Throws:

java.lang.Exception - if the input format is set and there is a problem with the expression

getExpression

public java.lang.String getExpression()

Get the expression

Returns:

the expression

invertSelectionTipText

public java.lang.String invertSelectionTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

getInvertSelection

public boolean getInvertSelection()

Get whether the supplied columns are to be select or unselect

Returns:

true if the supplied columns will be kept

setInvertSelection

public void setInvertSelection(boolean invert)

Set whether selected columns should be select or unselect. If true the selected columns are modified. If false the selected columns are not modified.

Parameters:

invert - the new invert setting

ignoreRangeTipText

public java.lang.String ignoreRangeTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

getIgnoreRange

public java.lang.String getIgnoreRange()

Get the current range selection.

Returns:

a string containing a comma separated list of ranges

setIgnoreRange

public void setIgnoreRange(java.lang.String rangeList)

Set which attributes are to be ignored

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

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Overrides:

getRevision in class Filter

Returns:

the revision

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