Package org.terrier.matching.models.basicmodel

Class BasicModel

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    Direct Known Subclasses:
    B, BM, Br, DFR_BM, IF, In, In_exp, P
    public abstract class BasicModel
extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable
    This class provides a contract for implementing the basic models for randomness in the DFR framework, for use with the DFRWeightingModel class. This is referred to as the component -log(prob1) in the DFR framework.
    Author:
    Ben He
    See Also:
    DFRWeightingModel, Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected Idf i
      The class used for computing the idf values.
      protected double numberOfDocuments
      The number of documents in the whole collection.
      protected double numberOfTokens
      The number of tokens in the whole collection

    • Constructor Summary

      Constructors 
      Constructor Description
      BasicModel()
      A default constructor that initialises the idf i attribute

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      BasicModel clone()
      Clone this weighting model
      abstract java.lang.String getInfo()
      Returns the name of the model.
      abstract double score​(double tf, double documentFrequency, double termFrequency, double keyFrequency, double documentLength)
      This method provides the contract for implementing weighting models.
      void setNumberOfDocuments​(double numOfDocs)
      Sets the number of documents in the collection.
      void setNumberOfTokens​(double numTokens)
      Set the number of tokens in the collection.
      double stirlingPower​(double n, double m)
      This method provides the contract for implementing the Stirling formula for the power series.

      • Methods inherited from class java.lang.Object

        equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • i

        protected Idf i
        The class used for computing the idf values.

      • numberOfDocuments

        protected double numberOfDocuments
        The number of documents in the whole collection.

      • numberOfTokens

        protected double numberOfTokens
        The number of tokens in the whole collection

    • Constructor Detail

      • BasicModel

        public BasicModel()
        A default constructor that initialises the idf i attribute

    • Method Detail

      • clone

        public BasicModel clone()
        Clone this weighting model
        Overrides:
        clone in class java.lang.Object

      • getInfo

        public abstract java.lang.String getInfo()
        Returns the name of the model.
        Returns:
        java.lang.String

      • setNumberOfDocuments

        public void setNumberOfDocuments​(double numOfDocs)
        Sets the number of documents in the collection.
        Parameters:
        numOfDocs - the number of documents in the collection.

      • setNumberOfTokens

        public void setNumberOfTokens​(double numTokens)
        Set the number of tokens in the collection.
        Parameters:
        numTokens - double The number of tokens in the collection.

      • score

        public abstract double score​(double tf,
                             double documentFrequency,
                             double termFrequency,
                             double keyFrequency,
                             double documentLength)
        This method provides the contract for implementing weighting models.
        Parameters:
        tf - The term frequency in the document
        documentFrequency - The document frequency of the term
        termFrequency - The term frequency of the term in the collection
        keyFrequency - The normalised query term frequency.
        documentLength - The length of the document.
        Returns:
        the score returned by the implemented weighting model.

      • stirlingPower

        public double stirlingPower​(double n,
                            double m)
        This method provides the contract for implementing the Stirling formula for the power series.
        Parameters:
        n - The parameter of the Stirling formula.
        m - The parameter of the Stirling formula.
        Returns:
        the approximation of the power series