ttable.h

解码器是基于短语的统计机器翻译系统的核心模块

/*
* TTable.h  -  Bilingual Phrases Translation Table
*
* Copyright (C) 2006 by Zhongjun He <[e-mail]> 
                Multilingual Interaction Technology and Evaluation Laboratory, ICT, CAS

* Begin       : 04/13/2006
* Last Change : 04/13/2006
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#ifndef TTABLE_H
#define TTABLE_H

#include <map>
#include <strstream>
#include <string>
#include <vector>
#include <algorithm>
#include <math.h>
#include <iostream>
#include <fstream>

#include "Function.h"
#include "Mtdefs.h"

using namespace std;

class TTable
{
public:

	TTable();


	//set translation probability  weight and talbe limit
	void Set(const vector<double> &l, const int lt);

	// insert a bilingual phrase 
	void Insert(const string &cp,const string &ep, const vector<double> &prob);

	// get phrase translation probability   
	vector<double> GetProb(const string &cp, const string &ep);

	// write to file
	void WriteToFile(const char* fileName);

	// read from file
	void ReadFromFile(const char* fileName);

	// get English translations for a Chinese phrase
	bool GetTranslations(const string &cp, map<string, vector<double> > &translation);

	int prob_num;//number of translation probability, default is 4: p(f|e) lex(f|e) p(e|f) lex(e|f)


private:

   	// for reading bilingual phrases 
	bool split(const string &line, string &cp, string &ep, vector<double> &prob);
	
	// compute word number
	int WordLen(const string &s);

	map<string,map<string,vector<double> > > tmap;// phrase translation table

	vector<double> lambda;//tanslation weight

	int bp_limit;

};


#endif