/// <summary> Computes a score factor for a simple term and returns an explanation /// for that score factor. /// /// <p/> /// The default implementation uses: /// /// <pre> /// idf(searcher.docFreq(term), searcher.maxDoc()); /// </pre> /// /// Note that {@link Searcher#MaxDoc()} is used instead of /// {@link Mono.Lucene.Net.Index.IndexReader#NumDocs()} because it is /// proportional to {@link Searcher#DocFreq(Term)} , i.e., when one is /// inaccurate, so is the other, and in the same direction. /// /// </summary> /// <param name="term">the term in question /// </param> /// <param name="searcher">the document collection being searched /// </param> /// <returns> an IDFExplain object that includes both an idf score factor /// and an explanation for the term. /// </returns> /// <throws> IOException </throws> public virtual IDFExplanation IdfExplain(Term term, Searcher searcher) { if (SupportedMethods.overridesTermIDF) { float idf = Idf(term, searcher); return(new AnonymousClassIDFExplanation(idf, this)); } int df = searcher.DocFreq(term); int max = searcher.MaxDoc(); float idf2 = Idf(df, max); return(new AnonymousClassIDFExplanation1(df, max, idf2, this)); }
/// <summary> Computes a score factor for a phrase. /// /// <p/> /// The default implementation sums the idf factor for /// each term in the phrase. /// /// </summary> /// <param name="terms">the terms in the phrase /// </param> /// <param name="searcher">the document collection being searched /// </param> /// <returns> an IDFExplain object that includes both an idf /// score factor for the phrase and an explanation /// for each term. /// </returns> /// <throws> IOException </throws> public virtual IDFExplanation idfExplain(System.Collections.ICollection terms, Searcher searcher) { if (SupportedMethods.overridesCollectionIDF) { float idf = Idf(terms, searcher); return(new AnonymousClassIDFExplanation2(idf, this)); } int max = searcher.MaxDoc(); float idf2 = 0.0f; System.Text.StringBuilder exp = new System.Text.StringBuilder(); foreach (Term term in terms) { int df = searcher.DocFreq(term); idf2 += Idf(df, max); exp.Append(" "); exp.Append(term.Text()); exp.Append("="); exp.Append(df); } float fIdf = idf2; return(new AnonymousClassIDFExplanation3(fIdf, exp, this)); }
public virtual float Idf(Term term, Searcher searcher) { return(Idf(searcher.DocFreq(term), searcher.MaxDoc())); }
/// <summary> Computes a score factor for a phrase. /// /// <p/> /// The default implementation sums the idf factor for /// each term in the phrase. /// /// </summary> /// <param name="terms">the terms in the phrase /// </param> /// <param name="searcher">the document collection being searched /// </param> /// <returns> an IDFExplain object that includes both an idf /// score factor for the phrase and an explanation /// for each term. /// </returns> /// <throws> IOException </throws> public virtual IDFExplanation idfExplain(System.Collections.ICollection terms, Searcher searcher) { if (SupportedMethods.overridesCollectionIDF) { float idf = Idf(terms, searcher); return new AnonymousClassIDFExplanation2(idf, this); } int max = searcher.MaxDoc(); float idf2 = 0.0f; System.Text.StringBuilder exp = new System.Text.StringBuilder(); foreach (Term term in terms) { int df = searcher.DocFreq(term); idf2 += Idf(df, max); exp.Append(" "); exp.Append(term.Text()); exp.Append("="); exp.Append(df); } float fIdf = idf2; return new AnonymousClassIDFExplanation3(fIdf, exp, this); }
/// <summary> Computes a score factor for a simple term and returns an explanation /// for that score factor. /// /// <p/> /// The default implementation uses: /// /// <pre> /// idf(searcher.docFreq(term), searcher.maxDoc()); /// </pre> /// /// Note that {@link Searcher#MaxDoc()} is used instead of /// {@link Mono.Lucene.Net.Index.IndexReader#NumDocs()} because it is /// proportional to {@link Searcher#DocFreq(Term)} , i.e., when one is /// inaccurate, so is the other, and in the same direction. /// /// </summary> /// <param name="term">the term in question /// </param> /// <param name="searcher">the document collection being searched /// </param> /// <returns> an IDFExplain object that includes both an idf score factor /// and an explanation for the term. /// </returns> /// <throws> IOException </throws> public virtual IDFExplanation IdfExplain(Term term, Searcher searcher) { if (SupportedMethods.overridesTermIDF) { float idf = Idf(term, searcher); return new AnonymousClassIDFExplanation(idf, this); } int df = searcher.DocFreq(term); int max = searcher.MaxDoc(); float idf2 = Idf(df, max); return new AnonymousClassIDFExplanation1(df, max, idf2, this); }
public virtual float Idf(Term term, Searcher searcher) { return Idf(searcher.DocFreq(term), searcher.MaxDoc()); }