Package weka.classifiers.trees

Class J48

    • Constructor Detail

      • J48

        public J48()

    • Method Detail

      • globalInfo

        public java.lang.String globalInfo()
        Returns a string describing classifier
        Returns:
        a description 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

      • buildClassifier

        public void buildClassifier​(Instances instances)
                     throws java.lang.Exception
        Generates the classifier.
        Specified by:
        buildClassifier in interface Classifier
        Parameters:
        instances - the data to train the classifier with
        Throws:
        java.lang.Exception - if classifier can't be built successfully

      • classifyInstance

        public double classifyInstance​(Instance instance)
                        throws java.lang.Exception
        Classifies an instance.
        Specified by:
        classifyInstance in interface Classifier
        Overrides:
        classifyInstance in class AbstractClassifier
        Parameters:
        instance - the instance to classify
        Returns:
        the classification for the instance
        Throws:
        java.lang.Exception - if instance can't be classified successfully

      • distributionForInstance

        public final double[] distributionForInstance​(Instance instance)
                                       throws java.lang.Exception
        Returns class probabilities for an instance.
        Specified by:
        distributionForInstance in interface Classifier
        Overrides:
        distributionForInstance in class AbstractClassifier
        Parameters:
        instance - the instance to calculate the class probabilities for
        Returns:
        the class probabilities
        Throws:
        java.lang.Exception - if distribution can't be computed successfully

      • graphType

        public int graphType()
        Returns the type of graph this classifier represents.
        Specified by:
        graphType in interface Drawable
        Returns:
        Drawable.TREE

      • graph

        public java.lang.String graph()
                       throws java.lang.Exception
        Returns graph describing the tree.
        Specified by:
        graph in interface Drawable
        Returns:
        the graph describing the tree
        Throws:
        java.lang.Exception - if graph can't be computed

      • prefix

        public java.lang.String prefix()
                        throws java.lang.Exception
        Returns tree in prefix order.
        Specified by:
        prefix in interface Matchable
        Returns:
        the tree in prefix order
        Throws:
        java.lang.Exception - if something goes wrong

      • toSource

        public java.lang.String toSource​(java.lang.String className)
                          throws java.lang.Exception
        Returns tree as an if-then statement.
        Specified by:
        toSource in interface Sourcable
        Parameters:
        className - the name of the Java class
        Returns:
        the tree as a Java if-then type statement
        Throws:
        java.lang.Exception - if something goes wrong

      • listOptions

        public java.util.Enumeration<Option> listOptions()
        Returns an enumeration describing the available options. Valid options are:

        -U
        Use unpruned tree.

        -C confidence
        Set confidence threshold for pruning. (Default: 0.25)

        -M number
        Set minimum number of instances per leaf. (Default: 2)

        -R
        Use reduced error pruning. No subtree raising is performed.

        -N number
        Set number of folds for reduced error pruning. One fold is used as the pruning set. (Default: 3)

        -B
        Use binary splits for nominal attributes.

        -S
        Don't perform subtree raising.

        -L
        Do not clean up after the tree has been built. -A
        If set, Laplace smoothing is used for predicted probabilites.

        -Q
        The seed for reduced-error pruning.

        Specified by:
        listOptions in interface OptionHandler
        Overrides:
        listOptions in class AbstractClassifier
        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: 

         -U
  Use unpruned tree.
 
         -O
  Do not collapse tree.
 
         -C <pruning confidence>
  Set confidence threshold for pruning.
  (default 0.25)
 
         -M <minimum number of instances>
  Set minimum number of instances per leaf.
  (default 2)
 
         -R
  Use reduced error pruning.
 
         -N <number of folds>
  Set number of folds for reduced error
  pruning. One fold is used as pruning set.
  (default 3)
 
         -B
  Use binary splits only.
 
         -S
  Don't perform subtree raising.
 
         -L
  Do not clean up after the tree has been built.
 
         -A
  Laplace smoothing for predicted probabilities.
 
         -J
  Do not use MDL correction for info gain on numeric attributes.
 
         -Q <seed>
  Seed for random data shuffling (default 1).
 
         -doNotMakeSplitPointActualValue
  Do not make split point actual value.
        Specified by:
        setOptions in interface OptionHandler
        Overrides:
        setOptions in class AbstractClassifier
        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 Classifier.
        Specified by:
        getOptions in interface OptionHandler
        Overrides:
        getOptions in class AbstractClassifier
        Returns:
        an array of strings suitable for passing to setOptions

      • 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

      • getSeed

        public int getSeed()
        Get the value of Seed.
        Returns:
        Value of Seed.

      • setSeed

        public void setSeed​(int newSeed)
        Set the value of Seed.
        Parameters:
        newSeed - Value to assign to Seed.

      • useLaplaceTipText

        public java.lang.String useLaplaceTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getUseLaplace

        public boolean getUseLaplace()
        Get the value of useLaplace.
        Returns:
        Value of useLaplace.

      • setUseLaplace

        public void setUseLaplace​(boolean newuseLaplace)
        Set the value of useLaplace.
        Parameters:
        newuseLaplace - Value to assign to useLaplace.

      • useMDLcorrectionTipText

        public java.lang.String useMDLcorrectionTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getUseMDLcorrection

        public boolean getUseMDLcorrection()
        Get the value of useMDLcorrection.
        Returns:
        Value of useMDLcorrection.

      • setUseMDLcorrection

        public void setUseMDLcorrection​(boolean newuseMDLcorrection)
        Set the value of useMDLcorrection.
        Parameters:
        newuseMDLcorrection - Value to assign to useMDLcorrection.

      • toString

        public java.lang.String toString()
        Returns a description of the classifier.
        Overrides:
        toString in class java.lang.Object
        Returns:
        a description of the classifier

      • toSummaryString

        public java.lang.String toSummaryString()
        Returns a superconcise version of the model
        Specified by:
        toSummaryString in interface Summarizable
        Returns:
        a summary of the model

      • measureTreeSize

        public double measureTreeSize()
        Returns the size of the tree
        Returns:
        the size of the tree

      • measureNumLeaves

        public double measureNumLeaves()
        Returns the number of leaves
        Returns:
        the number of leaves

      • measureNumRules

        public double measureNumRules()
        Returns the number of rules (same as number of leaves)
        Returns:
        the number of rules

      • enumerateMeasures

        public java.util.Enumeration<java.lang.String> enumerateMeasures()
        Returns an enumeration of the additional measure names
        Specified by:
        enumerateMeasures in interface AdditionalMeasureProducer
        Returns:
        an enumeration of the measure names

      • getMeasure

        public double getMeasure​(java.lang.String additionalMeasureName)
        Returns the value of the named measure
        Specified by:
        getMeasure in interface AdditionalMeasureProducer
        Parameters:
        additionalMeasureName - the name of the measure to query for its value
        Returns:
        the value of the named measure
        Throws:
        java.lang.IllegalArgumentException - if the named measure is not supported

      • unprunedTipText

        public java.lang.String unprunedTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getUnpruned

        public boolean getUnpruned()
        Get the value of unpruned.
        Returns:
        Value of unpruned.

      • setUnpruned

        public void setUnpruned​(boolean v)
        Set the value of unpruned. Turns reduced-error pruning off if set.
        Parameters:
        v - Value to assign to unpruned.

      • collapseTreeTipText

        public java.lang.String collapseTreeTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getCollapseTree

        public boolean getCollapseTree()
        Get the value of collapseTree.
        Returns:
        Value of collapseTree.

      • setCollapseTree

        public void setCollapseTree​(boolean v)
        Set the value of collapseTree.
        Parameters:
        v - Value to assign to collapseTree.

      • confidenceFactorTipText

        public java.lang.String confidenceFactorTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getConfidenceFactor

        public float getConfidenceFactor()
        Get the value of CF.
        Returns:
        Value of CF.

      • setConfidenceFactor

        public void setConfidenceFactor​(float v)
        Set the value of CF.
        Parameters:
        v - Value to assign to CF.

      • minNumObjTipText

        public java.lang.String minNumObjTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getMinNumObj

        public int getMinNumObj()
        Get the value of minNumObj.
        Returns:
        Value of minNumObj.

      • setMinNumObj

        public void setMinNumObj​(int v)
        Set the value of minNumObj.
        Parameters:
        v - Value to assign to minNumObj.

      • reducedErrorPruningTipText

        public java.lang.String reducedErrorPruningTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getReducedErrorPruning

        public boolean getReducedErrorPruning()
        Get the value of reducedErrorPruning.
        Returns:
        Value of reducedErrorPruning.

      • setReducedErrorPruning

        public void setReducedErrorPruning​(boolean v)
        Set the value of reducedErrorPruning. Turns unpruned trees off if set.
        Parameters:
        v - Value to assign to reducedErrorPruning.

      • numFoldsTipText

        public java.lang.String numFoldsTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getNumFolds

        public int getNumFolds()
        Get the value of numFolds.
        Returns:
        Value of numFolds.

      • setNumFolds

        public void setNumFolds​(int v)
        Set the value of numFolds.
        Parameters:
        v - Value to assign to numFolds.

      • binarySplitsTipText

        public java.lang.String binarySplitsTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getBinarySplits

        public boolean getBinarySplits()
        Get the value of binarySplits.
        Returns:
        Value of binarySplits.

      • setBinarySplits

        public void setBinarySplits​(boolean v)
        Set the value of binarySplits.
        Parameters:
        v - Value to assign to binarySplits.

      • subtreeRaisingTipText

        public java.lang.String subtreeRaisingTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getSubtreeRaising

        public boolean getSubtreeRaising()
        Get the value of subtreeRaising.
        Returns:
        Value of subtreeRaising.

      • setSubtreeRaising

        public void setSubtreeRaising​(boolean v)
        Set the value of subtreeRaising.
        Parameters:
        v - Value to assign to subtreeRaising.

      • 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()
        Check whether instance data is to be saved.
        Returns:
        true if instance data is saved

      • setSaveInstanceData

        public void setSaveInstanceData​(boolean v)
        Set whether instance data is to be saved.
        Parameters:
        v - true if instance data is to be saved

      • doNotMakeSplitPointActualValueTipText

        public java.lang.String doNotMakeSplitPointActualValueTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getDoNotMakeSplitPointActualValue

        public boolean getDoNotMakeSplitPointActualValue()
        Gets the value of doNotMakeSplitPointActualValue.
        Returns:
        the value

      • setDoNotMakeSplitPointActualValue

        public void setDoNotMakeSplitPointActualValue​(boolean m_doNotMakeSplitPointActualValue)
        Sets the value of doNotMakeSplitPointActualValue.
        Parameters:
        m_doNotMakeSplitPointActualValue - the value to set

      • generatePartition

        public void generatePartition​(Instances data)
                       throws java.lang.Exception
        Builds the classifier to generate a partition.
        Specified by:
        generatePartition in interface PartitionGenerator
        Throws:
        java.lang.Exception

      • getMembershipValues

        public double[] getMembershipValues​(Instance inst)
                             throws java.lang.Exception
        Computes an array that indicates node membership.
        Specified by:
        getMembershipValues in interface PartitionGenerator
        Throws:
        java.lang.Exception

      • numElements

        public int numElements()
                throws java.lang.Exception
        Returns the number of elements in the partition.
        Specified by:
        numElements in interface PartitionGenerator
        Throws:
        java.lang.Exception

      • main

        public static void main​(java.lang.String[] argv)
        Main method for testing this class
        Parameters:
        argv - the commandline options