Class Hiemstra_LM

  • All Implemented Interfaces:, java.lang.Cloneable, Model

    public class Hiemstra_LM
    extends WeightingModel
    This class implements the Hiemstra LM weighting model. A default lambda value of 0.15 is used, according to section 5.2.3 of Djoerd Hiemstra's thesis: Using language models for information retrieval. PhD Thesis, Centre for Telematics and Information Technology, University of Twente, 2001.
    Jie Peng
    See Also:
    Serialized Form
    • Constructor Detail

      • Hiemstra_LM

        public Hiemstra_LM()
        A default constructor. Uses the default value of lambda=0.15.
      • Hiemstra_LM

        public Hiemstra_LM​(double lambda)
        Constructs an instance of this class with the specified value for the parameter lambda.
        lambda - the smoothing parameter.
    • Method Detail

      • getInfo

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

        public final double score​(double tf,
                                  double docLength)
        Uses Hiemestra_LM to compute a weight for a term in a document.
        Specified by:
        score in class WeightingModel
        tf - The term frequency in the document
        docLength - the document's length
        the score assigned to a document with the given tf and docLength, and other preset parameters