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
the score assigned to a document with the given
tf and docLength, and other preset parameters
public final double score(double tf,
This method provides the contract for implementing weighting models.
As of Terrier 3.6, the 5-parameter score method is being deprecated
since it is not used. The two parameter score method should be used
instead. Tagged for removal in a later version.