Class DFR_BM

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable

    public class DFR_BM
    extends BasicModel
    This class implements the DFR BM weighting model, which is an approximation of BM25 in the DFR framework. Feel free to combine the DFR_BM model with any frequency normalisation method. However, it is NOT recommended to use DFR_BM with the first normalisation for after effect. For example, to use the DFR_BM model with the normalisation 2, add the following line in file etc/trec.models: DFRWeightingModel(DFR_BM, , 2) Leave the space between the comas blank so that the first normalisation is disabled.
    Author:
    Ben He
    See Also:
    Serialized Form
    • Constructor Summary

      Constructors 
      Constructor Description
      DFR_BM()
      A default constructor.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String getInfo()
      Returns the name of the model.
      double score​(double tf, double documentFrequency, double termFrequency, double keyFrequency, double documentLength)
      This method computes the score for the implemented weighting model.
      • Methods inherited from class java.lang.Object

        equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • modelName

        protected java.lang.String modelName
        The name of the model.
    • Constructor Detail

      • DFR_BM

        public DFR_BM()
        A default constructor.
    • Method Detail

      • getInfo

        public java.lang.String getInfo()
        Returns the name of the model.
        Specified by:
        getInfo in class BasicModel
        Returns:
        the name of the model
      • score

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