RandomSearch

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

All Implemented Interfaces:

java.io.Serializable, StartSetHandler, OptionHandler, RevisionHandler, TechnicalInformationHandler
```
public class RandomSearch
extends ASSearch
implements StartSetHandler, OptionHandler, TechnicalInformationHandler
```
RandomSearch :

Performs a Random search in the space of attribute subsets. If no start set is supplied, Random search starts from a random point and reports the best subset found. If a start set is supplied, Random searches randomly for subsets that are as good or better than the start point with the same or or fewer attributes. Using RandomSearch in conjunction with a start set containing all attributes equates to the LVF algorithm of Liu and Setiono (ICML-96).

For more information see:

H. Liu, R. Setiono: A probabilistic approach to feature selection - A filter solution. In: 13th International Conference on Machine Learning, 319-327, 1996.
BibTeX:
```
 @inproceedings{Liu1996,
    author = {H. Liu and R. Setiono},
    booktitle = {13th International Conference on Machine Learning},
    pages = {319-327},
    title = {A probabilistic approach to feature selection - A filter solution},
    year = {1996}
 }
 
```
Valid options are:
```
 -P <start set>
  Specify a starting set of attributes.
  Eg. 1,3,5-7.
  If a start point is supplied,
  random search evaluates the start
  point and then randomly looks for
  subsets that are as good as or better
  than the start point with the same
  or lower cardinality.
```
```
 -F <percent> 
  Percent of search space to consider.
  (default = 25%).
```
```
 -V
  Output subsets as the search progresses.
  (default = false).
```
```
 -seed <num>
  Random seed
  (default = 1)
```
Version:

$Revision: 8949 $

Author:

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

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description

RandomSearch()
Constructor

Constructors
Constructor and Description
`RandomSearch()` Constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`java.lang.String[]`	`getOptions()` Gets the current settings of RandomSearch.
`java.lang.String`	`getRevision()` Returns the revision string.
`double`	`getSearchPercent()` get the percentage of the search space to consider
`int`	`getSeed()` Get the random seed to use
`java.lang.String`	`getStartSet()` Returns a list of attributes (and or attribute ranges) as a String
`TechnicalInformation`	`getTechnicalInformation()` Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
`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
`java.lang.String`	`seedTipText()` 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`	`setSeed(int seed)` Set the random seed to use
`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, makeCopies

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
  - getTechnicalInformation
```
public TechnicalInformation getTechnicalInformation()
```
    Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
    
    Specified by:
    
    getTechnicalInformation in interface TechnicalInformationHandler
    
    Returns:
    
    the technical information about this class
  - 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 <start set>
  Specify a starting set of attributes.
  Eg. 1,3,5-7.
  If a start point is supplied,
  random search evaluates the start
  point and then randomly looks for
  subsets that are as good as or better
  than the start point with the same
  or lower cardinality.
```
```
 -F <percent> 
  Percent of search space to consider.
  (default = 25%).
```
```
 -V
  Output subsets as the search progresses.
  (default = false).
```
```
 -seed <num>
  Random seed
  (default = 1)
```
    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 RandomSearch.
    
    Specified by:
    
    getOptions in interface OptionHandler
    
    Returns:
    
    an array of strings suitable for passing to setOptions()
  - 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)
  - seedTipText
```
public java.lang.String seedTipText()
```
    Returns the tip text for this property
    
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - setSeed
```
public void setSeed(int seed)
```
    Set the random seed to use
    
    Parameters:
    
    seed - the seed to use
  - getSeed
```
public int getSeed()
```
    Get the random seed to use
    
    Returns:
    
    the random seed
  - getSearchPercent
```
public double getSearchPercent()
```
    get the percentage of the search space to consider
    
    Returns:
    
    the percent of the search space explored
  - 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:
    
    ASEval - the attribute evaluator to guide the search
    
    data - the training instances.
    
    Returns:
    
    an array (not necessarily ordered) of selected attribute indexes
    
    Throws:
    
    java.lang.Exception - if the search can't be completed
  - getRevision
```
public java.lang.String getRevision()
```
    Returns the revision string.
    
    Specified by:
    
    getRevision in interface RevisionHandler
    
    Overrides:
    
    getRevision in class ASSearch
    
    Returns:
    
    the revision

Class RandomSearch

Constructor Summary

Method Summary

Methods inherited from class weka.attributeSelection.ASSearch

Methods inherited from class java.lang.Object

Constructor Detail

RandomSearch

Method Detail

globalInfo

getTechnicalInformation

listOptions

setOptions

getOptions

startSetTipText

setStartSet

getStartSet

verboseTipText

setVerbose

getVerbose

searchPercentTipText

setSearchPercent

seedTipText

setSeed

getSeed

getSearchPercent

toString

search

getRevision