Class RuleItem

java.lang.Object
weka.associations.RuleItem
All Implemented Interfaces:
Serializable, Comparable, RevisionHandler

public class RuleItem extends Object implements Comparable, Serializable, RevisionHandler
Class for storing an (class) association rule. The premise and the consequence are stored each as separate item sets. For every rule their expected predictive accuracy and the time of generation is stored. These two measures allow to introduce a sort order for rules.
Version:
$Revision: 1.5 $
Author:
Stefan Mutter
See Also:
  • Constructor Summary

    Constructors
    Constructor
    Description
    Constructor for an empty RuleItem
    RuleItem(ItemSet premise, ItemSet consequence, int genTime, int ruleSupport, double[] m_midPoints, Hashtable m_priors)
    Constructor
    Constructor that generates a RuleItem out of a given one
  • Method Summary

    Modifier and Type
    Method
    Description
    double
    Gets the expected predictive accuracy of a rule
    int
    compares two RuleItems and allows an ordering concerning expected predictive accuracy and time of generation Note: this class has a natural ordering that is inconsistent with equals
    Gets the consequence of a rule
    boolean
    returns whether two RuleItems are equal
    generateRuleItem(ItemSet premise, ItemSet consequence, Instances instances, int genTime, int minRuleCount, double[] m_midPoints, Hashtable m_priors)
    Constructs a new RuleItem if the support of the given rule is above the support threshold.
    Returns the revision string.
    Gets the premise of a rule

    Methods inherited from class java.lang.Object

    getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • RuleItem

      public RuleItem()
      Constructor for an empty RuleItem
    • RuleItem

      public RuleItem(RuleItem toCopy)
      Constructor that generates a RuleItem out of a given one
      Parameters:
      toCopy - RuleItem to copy
    • RuleItem

      public RuleItem(ItemSet premise, ItemSet consequence, int genTime, int ruleSupport, double[] m_midPoints, Hashtable m_priors)
      Constructor
      Parameters:
      premise - the premise of the future RuleItem
      consequence - the consequence of the future RuleItem
      genTime - the time of generation of the future RuleItem
      ruleSupport - support of the rule
      m_midPoints - the mid poitns of the intervals
      m_priors - Hashtable containing the estimated prior probablilities
  • Method Details

    • generateRuleItem

      public RuleItem generateRuleItem(ItemSet premise, ItemSet consequence, Instances instances, int genTime, int minRuleCount, double[] m_midPoints, Hashtable m_priors)
      Constructs a new RuleItem if the support of the given rule is above the support threshold.
      Parameters:
      premise - the premise
      consequence - the consequence
      instances - the instances
      genTime - the time of generation of the current premise and consequence
      minRuleCount - the support threshold
      m_midPoints - the mid points of the intervals
      m_priors - the estimated priori probabilities (in a hashtable)
      Returns:
      a RuleItem if its support is above the threshold, null otherwise
    • compareTo

      public int compareTo(Object o)
      compares two RuleItems and allows an ordering concerning expected predictive accuracy and time of generation Note: this class has a natural ordering that is inconsistent with equals
      Specified by:
      compareTo in interface Comparable
      Parameters:
      o - RuleItem to compare
      Returns:
      integer indicating the sort oder of the two RuleItems
    • equals

      public boolean equals(Object o)
      returns whether two RuleItems are equal
      Overrides:
      equals in class Object
      Parameters:
      o - RuleItem to compare
      Returns:
      true if the rules are equal, false otherwise
    • accuracy

      public double accuracy()
      Gets the expected predictive accuracy of a rule
      Returns:
      the expected predictive accuracy of a rule stored as a RuleItem
    • premise

      public ItemSet premise()
      Gets the premise of a rule
      Returns:
      the premise of a rule stored as a RuleItem
    • consequence

      public ItemSet consequence()
      Gets the consequence of a rule
      Returns:
      the consequence of a rule stored as a RuleItem
    • getRevision

      public String getRevision()
      Returns the revision string.
      Specified by:
      getRevision in interface RevisionHandler
      Returns:
      the revision