DefaultSimilarity.h

00001 //
00002 // Copyright(C) 2005--2006 Institute of Computing Tech, Chinese Academy of Sciences. 
00003 // All rights reserved.
00004 // This file is part of FirteX (www.firtex.org)
00005 //
00006 // Use of the FirteX is subject to the terms of the software license set forth in 
00007 // the LICENSE file included with this software, and also available at
00008 // http://www.firtex.org/license.html
00009 //
00010 // Author       : 郭瑞杰(GuoRuijie)
00011 // Email        : ruijieguo@software.ict.ac.cn,ruijieguo@gmail.com
00012 // Created      : 2006/5/9
00013 //
00014 #ifndef _DEFAULT_SIMILARITY_H
00015 #define _DEFAULT_SIMILARITY_H
00016 
00017 #include "Similarity.h"
00018 
00019 namespace firtex
00020 {
00021         namespace search
00022         {
00023                 class CDefaultSimilarity :      public CSimilarity
00024                 {
00025                 public:
00026                         CDefaultSimilarity(void);
00027                         virtual ~CDefaultSimilarity(void);
00028                 public:                         
00029 
00035                         float tf(float freq);
00036 
00043                         float idf(freq_t docFreq, count_t numDocs);
00044 
00045                         float sloppyFreq(int distance);
00046 
00047                         float lengthNorm(count_t numTerms);
00048 
00049                         float queryNorm(float sumOfSquaredWeights);
00050 
00051                         float coord(int overlap, int maxOverlap);
00052                 };
00053         }
00054 }
00055 
00056 
00057 #endif