weka.attributeSelection
Class RandomSearch

java.lang.Object
  |
  +--weka.attributeSelection.ASSearch
        |
        +--weka.attributeSelection.RandomSearch

All Implemented Interfaces:

OptionHandler, java.io.Serializable, StartSetHandler

public class RandomSearch

extends ASSearch

implements StartSetHandler, OptionHandler

Class for performing a random search.

Valid options are:

-P
Specify a starting set of attributes. Eg 1,4,7-9.

-F Percentage of the search space to consider. (default = 25).

-V
Verbose output. Output new best subsets as the search progresses.

Version:

$Revision: 1.12 $

Author:

Mark Hall (mhall@cs.waikato.ac.nz)

See Also:

Serialized Form

Constructor Summary

RandomSearch()
Constructor

Method Summary

java.lang.String[]	getOptions() Gets the current settings of RandomSearch.
double	getSearchPercent() get the percentage of the search space to consider
java.lang.String	getStartSet() Returns a list of attributes (and or attribute ranges) as a String
boolean	getVerbose() get whether or not output is verbose
java.lang.String	globalInfo() Returns a string describing this search method
java.util.Enumeration	listOptions() Returns an enumeration describing the available options.
int[]	search(ASEvaluation ASEval, Instances data) Searches the attribute subset space randomly.
java.lang.String	searchPercentTipText() Returns the tip text for this property
void	setOptions(java.lang.String[] options) Parses a given list of options.
void	setSearchPercent(double p) set the percentage of the search space to consider
void	setStartSet(java.lang.String startSet) Sets a starting set of attributes for the search.
void	setVerbose(boolean v) set whether or not to output new best subsets as the search proceeds
java.lang.String	startSetTipText() Returns the tip text for this property
java.lang.String	toString() prints a description of the search
java.lang.String	verboseTipText() Returns the tip text for this property

Methods inherited from class weka.attributeSelection.ASSearch

forName

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomSearch

public RandomSearch()

Constructor

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing this search method

Returns:

a description of the search 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. Valid options are:

-P
Specify a starting set of attributes. Eg 1,4,7-9.

-F Percentage of the search space to consider. (default = 25).

-V
Verbose output. Output new best subsets as the search progresses.

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

startSetTipText

public java.lang.String startSetTipText()

Returns the tip text for this property

Returns:

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

setStartSet

public void setStartSet(java.lang.String startSet)
                 throws java.lang.Exception

Sets a starting set of attributes for the search. It is the search method's responsibility to report this start set (if any) in its toString() method.

Specified by:

setStartSet in interface StartSetHandler

Parameters:

startSet - a string containing a list of attributes (and or ranges), eg. 1,2,6,10-15. "" indicates no start point. If a start point is supplied, random search evaluates the start point and then looks for subsets that are as good as or better than the start point with the same or lower cardinality.

Throws:

java.lang.Exception - if start set can't be set.

getStartSet

public java.lang.String getStartSet()

Returns a list of attributes (and or attribute ranges) as a String

Specified by:

getStartSet in interface StartSetHandler

Returns:

a list of attributes (and or attribute ranges)

verboseTipText

public java.lang.String verboseTipText()

Returns the tip text for this property

Returns:

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

setVerbose

public void setVerbose(boolean v)

set whether or not to output new best subsets as the search proceeds

Parameters:

v - true if output is to be verbose

getVerbose

public boolean getVerbose()

get whether or not output is verbose

Returns:

true if output is set to verbose

searchPercentTipText

public java.lang.String searchPercentTipText()

Returns the tip text for this property

Returns:

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

setSearchPercent

public void setSearchPercent(double p)

set the percentage of the search space to consider

Parameters:

p - percent of the search space ( 0 < p <= 100)

getSearchPercent

public double getSearchPercent()

get the percentage of the search space to consider

Returns:

the percent of the search space explored

getOptions

public java.lang.String[] getOptions()

Gets the current settings of RandomSearch.

Specified by:

getOptions in interface OptionHandler

Returns:

an array of strings suitable for passing to setOptions()

toString

public java.lang.String toString()

prints a description of the search

Overrides:

toString in class java.lang.Object

Returns:

a description of the search as a string

search

public int[] search(ASEvaluation ASEval,
                    Instances data)
             throws java.lang.Exception

Searches the attribute subset space randomly.

Specified by:

search in class ASSearch

Parameters:

data - the training instances.

ASEval - the attribute evaluator to guide the search

Returns:

an array (not necessarily ordered) of selected attribute indexes

Throws:

java.lang.Exception - if the search can't be completed