Package weka.clusterers

Class Cobweb

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable, Clusterer, UpdateableClusterer, CapabilitiesHandler, CapabilitiesIgnorer, CommandlineRunnable, 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)
     -save-data
  Save instance data.
     -S <num>
  Random number seed.
  (default 42)
     -output-debug-info
  If set, clusterer is run in debug mode and
  may output additional info to the console
     -do-not-check-capabilities
  If set, clusterer capabilities are not checked before clusterer is built
  (use with caution).
    Version:
    $Revision: 11556 $
    Author:
    Mark Hall
    See Also:
    RandomizableClusterer, Drawable, Serialized Form

    • 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

      • 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.

      • 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

      • getTreeRoot

        public Cobweb.CNode getTreeRoot()
        Get the root of the tree.
        Returns:
        the root of the tree.

      • 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

        @Deprecated
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)

      • 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)
         -save-data
  Save instance data.
         -S <num>
  Random number seed.
  (default 42)
         -output-debug-info
  If set, clusterer is run in debug mode and
  may output additional info to the console
         -do-not-check-capabilities
  If set, clusterer capabilities are not checked before clusterer is built
  (use with caution).
        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.

      • 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

      • 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