java.lang.Object
- weka.clusterers.AbstractClusterer
- - weka.clusterers.RandomizableClusterer
  - - weka.clusterers.Cobweb

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Clusterer, UpdateableClusterer, CapabilitiesHandler, Drawable, OptionHandler, Randomizable, RevisionHandler, TechnicalInformationHandler
```
public class Cobweb
extends RandomizableClusterer
implements Drawable, TechnicalInformationHandler, UpdateableClusterer
```
Class implementing the Cobweb and Classit clustering algorithms.

Note: the application of node operators (merging, splitting etc.) in terms of ordering and priority differs (and is somewhat ambiguous) between the original Cobweb and Classit papers. This algorithm always compares the best host, adding a new leaf, merging the two best hosts, and splitting the best host when considering where to place a new instance.

For more information see:

D. Fisher (1987). Knowledge acquisition via incremental conceptual clustering. Machine Learning. 2(2):139-172.

J. H. Gennari, P. Langley, D. Fisher (1990). Models of incremental concept formation. Artificial Intelligence. 40:11-61.
BibTeX:
```
 @article{Fisher1987,
    author = {D. Fisher},
    journal = {Machine Learning},
    number = {2},
    pages = {139-172},
    title = {Knowledge acquisition via incremental conceptual clustering},
    volume = {2},
    year = {1987}
 }
 
 @article{Gennari1990,
    author = {J. H. Gennari and P. Langley and D. Fisher},
    journal = {Artificial Intelligence},
    pages = {11-61},
    title = {Models of incremental concept formation},
    volume = {40},
    year = {1990}
 }
 
```
Valid options are:
```
 -A <acuity>
  Acuity.
  (default=1.0)
```
```
 -C <cutoff>
  Cutoff.
  (default=0.002)
```
```
 -S <num>
  Random number seed.
  (default 42)
```
Version:

$Revision: 6790 $

Author:

Mark Hall

See Also:

RandomizableClusterer, Drawable, Serialized Form

Field Summary
- Fields inherited from interface weka.core.Drawable
  BayesNet, Newick, NOT_DRAWABLE, TREE

Constructor Summary

Constructors
Constructor Description

Cobweb()
default constructor

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`java.lang.String`	`acuityTipText()`	Returns the tip text for this property
`void`	`addInstance(Instance newInstance)`	Deprecated. updateClusterer(Instance) should be used instead
`void`	`buildClusterer(Instances data)`	Builds the clusterer.
`int`	`clusterInstance(Instance instance)`	Classifies a given instance.
`java.lang.String`	`cutoffTipText()`	Returns the tip text for this property
`double`	`getAcuity()`	get the acuity value
`Capabilities`	`getCapabilities()`	Returns default capabilities of the clusterer.
`double`	`getCutoff()`	get the cutoff
`java.lang.String[]`	`getOptions()`	Gets the current settings of Cobweb.
`java.lang.String`	`getRevision()`	Returns the revision string.
`boolean`	`getSaveInstanceData()`	Get the value of saveInstances.
`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.
`java.lang.String`	`globalInfo()`	Returns a string describing this clusterer
`java.lang.String`	`graph()`	Generates the graph string of the Cobweb tree
`int`	`graphType()`	Returns the type of graphs this class represents
`java.util.Enumeration`	`listOptions()`	Returns an enumeration describing the available options.
`static void`	`main(java.lang.String[] argv)`	Main method.
`int`	`numberOfClusters()`	Returns the number of clusters.
`java.lang.String`	`saveInstanceDataTipText()`	Returns the tip text for this property
`java.lang.String`	`seedTipText()`	Returns the tip text for this property
`void`	`setAcuity(double a)`	set the acuity.
`void`	`setCutoff(double c)`	set the cutoff
`void`	`setOptions(java.lang.String[] options)`	Parses a given list of options.
`void`	`setSaveInstanceData(boolean newsaveInstances)`	Set the value of saveInstances.
`java.lang.String`	`toString()`	Returns a description of the clusterer as a string.
`void`	`updateClusterer(Instance newInstance)`	Adds an instance to the clusterer.
`void`	`updateFinished()`	Singals the end of the updating.

Methods inherited from class weka.clusterers.RandomizableClusterer
getSeed, setSeed

Methods inherited from class weka.clusterers.AbstractClusterer
distributionForInstance, forName, makeCopies, makeCopy

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Cobweb
```
public Cobweb()
```
    default constructor
- Method Detail
  - globalInfo
```
public java.lang.String globalInfo()
```
    Returns a string describing this clusterer
    
    Returns:
    
    a description of the evaluator 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
  - getCapabilities
```
public Capabilities getCapabilities()
```
    Returns default capabilities of the clusterer.
    
    Specified by:
    
    getCapabilities in interface CapabilitiesHandler
    
    Specified by:
    
    getCapabilities in interface Clusterer
    
    Overrides:
    
    getCapabilities in class AbstractClusterer
    
    Returns:
    
    the capabilities of this clusterer
    
    See Also:
    
    Capabilities
  - buildClusterer
```
public void buildClusterer(Instances data)
                    throws java.lang.Exception
```
    Builds the clusterer.
    
    Specified by:
    
    buildClusterer in interface Clusterer
    
    Specified by:
    
    buildClusterer in class AbstractClusterer
    
    Parameters:
    
    data - the training instances.
    
    Throws:
    
    java.lang.Exception - if something goes wrong.
  - updateFinished
```
public void updateFinished()
```
    Singals the end of the updating.
    
    Specified by:
    
    updateFinished in interface UpdateableClusterer
  - clusterInstance
```
public int clusterInstance(Instance instance)
                    throws java.lang.Exception
```
    Classifies a given instance.
    
    Specified by:
    
    clusterInstance in interface Clusterer
    
    Overrides:
    
    clusterInstance in class AbstractClusterer
    
    Parameters:
    
    instance - the instance to be assigned to a cluster
    
    Returns:
    
    the number of the assigned cluster as an interger if the class is enumerated, otherwise the predicted value
    
    Throws:
    
    java.lang.Exception - if instance could not be classified successfully
  - numberOfClusters
```
public int numberOfClusters()
```
    Returns the number of clusters.
    
    Specified by:
    
    numberOfClusters in interface Clusterer
    
    Specified by:
    
    numberOfClusters in class AbstractClusterer
    
    Returns:
    
    the number of clusters
  - updateClusterer
```
public void updateClusterer(Instance newInstance)
                     throws java.lang.Exception
```
    Adds an instance to the clusterer.
    
    Specified by:
    
    updateClusterer in interface UpdateableClusterer
    
    Parameters:
    
    newInstance - the instance to be added
    
    Throws:
    
    java.lang.Exception - if something goes wrong
  - addInstance
```
public void addInstance(Instance newInstance)
                 throws java.lang.Exception
```
    Deprecated.
    updateClusterer(Instance) should be used instead
    
    Adds an instance to the Cobweb tree.
    
    Parameters:
    
    newInstance - the instance to be added
    
    Throws:
    
    java.lang.Exception - if something goes wrong
    
    See Also:
    
    updateClusterer(Instance)
  - listOptions
```
public java.util.Enumeration listOptions()
```
    Returns an enumeration describing the available options.
    
    Specified by:
    
    listOptions in interface OptionHandler
    
    Overrides:
    
    listOptions in class RandomizableClusterer
    
    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:
    
    -A <acuity> Acuity. (default=1.0)
    
    -C <cutoff> Cutoff. (default=0.002)
    
    -S <num> Random number seed. (default 42)
    Specified by:
    
    setOptions in interface OptionHandler
    
    Overrides:
    
    setOptions in class RandomizableClusterer
    
    Parameters:
    
    options - the list of options as an array of strings
    
    Throws:
    
    java.lang.Exception - if an option is not supported
  - acuityTipText
```
public java.lang.String acuityTipText()
```
    Returns the tip text for this property
    
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - setAcuity
```
public void setAcuity(double a)
```
    set the acuity.
    
    Parameters:
    
    a - the acuity value
  - getAcuity
```
public double getAcuity()
```
    get the acuity value
    
    Returns:
    
    the acuity
  - cutoffTipText
```
public java.lang.String cutoffTipText()
```
    Returns the tip text for this property
    
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - setCutoff
```
public void setCutoff(double c)
```
    set the cutoff
    
    Parameters:
    
    c - the cutof
  - getCutoff
```
public double getCutoff()
```
    get the cutoff
    
    Returns:
    
    the cutoff
  - saveInstanceDataTipText
```
public java.lang.String saveInstanceDataTipText()
```
    Returns the tip text for this property
    
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - getSaveInstanceData
```
public boolean getSaveInstanceData()
```
    Get the value of saveInstances.
    
    Returns:
    
    Value of saveInstances.
  - setSaveInstanceData
```
public void setSaveInstanceData(boolean newsaveInstances)
```
    Set the value of saveInstances.
    
    Parameters:
    
    newsaveInstances - Value to assign to saveInstances.
  - getOptions
```
public java.lang.String[] getOptions()
```
    Gets the current settings of Cobweb.
    
    Specified by:
    
    getOptions in interface OptionHandler
    
    Overrides:
    
    getOptions in class RandomizableClusterer
    
    Returns:
    
    an array of strings suitable for passing to setOptions()
  - toString
```
public java.lang.String toString()
```
    Returns a description of the clusterer as a string.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a string describing the clusterer.
  - graphType
```
public int graphType()
```
    Returns the type of graphs this class represents
    
    Specified by:
    
    graphType in interface Drawable
    
    Returns:
    
    Drawable.TREE
  - graph
```
public java.lang.String graph()
                       throws java.lang.Exception
```
    Generates the graph string of the Cobweb tree
    
    Specified by:
    
    graph in interface Drawable
    
    Returns:
    
    a String value
    
    Throws:
    
    java.lang.Exception - if an error occurs
  - getRevision
```
public java.lang.String getRevision()
```
    Returns the revision string.
    
    Specified by:
    
    getRevision in interface RevisionHandler
    
    Overrides:
    
    getRevision in class AbstractClusterer
    
    Returns:
    
    the revision
  - seedTipText
```
public java.lang.String seedTipText()
```
    Returns the tip text for this property
    
    Overrides:
    
    seedTipText in class RandomizableClusterer
    
    Returns:
    
    tip text for this property suitable for displaying in the explorer/experimenter gui
  - main
```
public static void main(java.lang.String[] argv)
```
    Main method.
    
    Parameters:
    
    argv - the commandline options

Class Cobweb

Field Summary

Fields inherited from interface weka.core.Drawable

Constructor Summary

Method Summary

Methods inherited from class weka.clusterers.RandomizableClusterer

Methods inherited from class weka.clusterers.AbstractClusterer

Methods inherited from class java.lang.Object

Constructor Detail

Cobweb

Method Detail

globalInfo

getTechnicalInformation

getCapabilities

buildClusterer

updateFinished

clusterInstance

numberOfClusters

updateClusterer

addInstance

listOptions

setOptions

acuityTipText

setAcuity

getAcuity

cutoffTipText

setCutoff

getCutoff

saveInstanceDataTipText

getSaveInstanceData

setSaveInstanceData

getOptions

toString

graphType

graph

getRevision

seedTipText

main