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Diffstat (limited to 'mgizapp/src/transpair_modelhmm.h')
| -rw-r--r-- | mgizapp/src/transpair_modelhmm.h | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/mgizapp/src/transpair_modelhmm.h b/mgizapp/src/transpair_modelhmm.h new file mode 100644 index 0000000..2b38913 --- /dev/null +++ b/mgizapp/src/transpair_modelhmm.h @@ -0,0 +1,223 @@ +/* + +Copyright (C) 2000,2001 Franz Josef Och (RWTH Aachen - Lehrstuhl fuer Informatik VI) + +This file is part of GIZA++ ( extension of GIZA ). + +This program is free software; you can redistribute it and/or +modify it under the terms of the GNU General Public License +as published by the Free Software Foundation; either version 2 +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 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 transpair_modelhmm_h_fjo_defined +#define transpair_modelhmm_h_fjo_defined +#include "Array2.h" +#include "defs.h" +#include "Vector.h" +#include "NTables.h" +#include "ATables.h" +#include "TTables.h" +#include "alignment.h" +#include <math.h> +#include "transpair_model2.h" +#include "ForwardBackward.h" +#include "hmm.h" + +class transpair_modelhmm : public transpair_model2 +{ + public: + typedef transpair_modelhmm simpler_transpair_model; + HMMNetwork*net; + transpair_modelhmm(const Vector<WordIndex>&es, const Vector<WordIndex>&fs, const tmodel<COUNT, PROB>&tTable, + const amodel<PROB>&aTable,const amodel<PROB>&,const nmodel<PROB>&, + double, double,const hmm*h) + : transpair_model2(es,fs,tTable,aTable),net(h->makeHMMNetwork(es,fs,0)) + {} + ~transpair_modelhmm() { delete net; } + int modelnr()const{return 6;} + LogProb scoreOfMove(const alignment&a, WordIndex _new_i, WordIndex j,double=-1.0)const + { + int new_i=_new_i; + LogProb change=1.0; + int old_i=a(j); + if (old_i == new_i) + change=1.0; + else + { + int theJ=j-1; + old_i--; + new_i--; + int jj=j-1; + while(jj>0&&a(jj)==0) + jj--; + int theIPrev= (jj>0)?(a(jj)-1):0; + if( j>1&&a(j-1)==0 ) + theIPrev+=l; + if( old_i==-1 ){old_i = theIPrev;if(old_i<int(l))old_i+=l;} + if( new_i==-1 ){new_i = theIPrev;if(new_i<int(l))new_i+=l;} + int theIPrevOld=theIPrev,theIPrevNew=theIPrev; + if( theJ==0 ) + { + change*=net->getAlphainit(new_i)/net->getAlphainit(old_i); + } + do + { + if( new_i!=old_i ) + { + change*=net->nodeProb(new_i,theJ)/net->nodeProb(old_i,theJ); + } + if( theJ>0) + change*=net->outProb(theJ,theIPrevNew,new_i)/net->outProb(theJ,theIPrevOld,old_i); + theIPrevOld=old_i; + theIPrevNew=new_i; + theJ++; + if( theJ<int(m) && a(theJ+1)==0 ) + { + if( new_i<int(l)) new_i+=l; + if( old_i<int(l)) old_i+=l; + } + } while( theJ<int(m) && a(theJ+1)==0 ); + if(theJ==int(m)) + { + change*=net->getBetainit(new_i)/net->getBetainit(old_i); + } + else + { + new_i=a(theJ+1)-1; + if( new_i==-1) + new_i=theIPrevNew; + change*=net->outProb(theJ,theIPrevNew,new_i)/net->outProb(theJ,theIPrevOld,new_i); + } + } + return change; + } + LogProb scoreOfAlignmentForChange(const alignment&)const + {return -1.0; } + LogProb scoreOfSwap(const alignment&a, WordIndex j1, WordIndex j2,double=-1.0)const + { + return _scoreOfSwap(a,j1,j2); + } + LogProb _scoreOfMove(const alignment&a, WordIndex new_i, WordIndex j,double=-1.0)const + { + alignment b(a); + b.set(j, new_i); + LogProb a_prob=prob_of_target_and_alignment_given_source(a); + LogProb b_prob=prob_of_target_and_alignment_given_source(b); + if( a_prob ) + return b_prob/a_prob; + else if( b_prob ) + return 1e20; + else + return 1.0; + } + LogProb _scoreOfSwap(const alignment&a, WordIndex j1, WordIndex j2,double=-1.0)const + { + WordIndex aj1=a(j1),aj2=a(j2); + if( aj1==aj2 ) + return 1.0; + LogProb a_prob=prob_of_target_and_alignment_given_source(a); + + /*alignment b(a); + b.set(j1, a(j2)); + b.set(j2, a(j1)); + LogProb b_prob=prob_of_target_and_alignment_given_source(b);*/ + + const_cast<alignment&>(a).set(j1,aj2); + const_cast<alignment&>(a).set(j2,aj1); + LogProb b_prob=prob_of_target_and_alignment_given_source(a); + const_cast<alignment&>(a).set(j1,aj1); + const_cast<alignment&>(a).set(j2,aj2); + + if( a_prob ) + return b_prob/a_prob; + else if( b_prob ) + return 1e20; + else + return 1.0; + } + inline friend ostream&operator<<(ostream&out, const transpair_modelhmm&) + { + return out << "NO-OUTPUT for transpair_modelhmm\n"; + } + LogProb prob_of_target_and_alignment_given_source(const alignment&al,bool verbose=0)const + { + double prob=1.0; + int theIPrev=0; + for(unsigned int j=1;j<=m;j++) + { + int theJ=j-1; + int theI=al(j)-1; + if( theI==-1 ) + theI=(theIPrev%l)+l; + prob*=net->nodeProb(theI,theJ); + if( verbose ) + cout << "NP " << net->nodeProb(theI,theJ) << ' '; + if( j==1 ) + { + prob*=net->getAlphainit(theI); + if( verbose ) + cout << "AP0 " << net->getAlphainit(theI) << ' '; + } + else + { + prob*=net->outProb(theJ,theIPrev,theI); + if( verbose ) + cout << "AP1 " << net->outProb(theJ,theIPrev,theI) << ' '; + } + theIPrev=theI; + if( j==m ) + { + prob*=net->getBetainit(theI); + if( verbose ) + cout << "AP2 " << net->getBetainit(theI) << ' '; + } + if( verbose ) + cout << "j:"<<theJ<<" i:"<<theI << "; "; + } + if( verbose ) + cout << '\n'; + return prob*net->finalMultiply; + } + void computeScores(const alignment&al,vector<double>&d)const + { + double prob1=1.0,prob2=1.0; + int theIPrev=0; + for(unsigned int j=1;j<=m;j++) + { + int theJ=j-1; + int theI=al(j)-1; + if( theI==-1 ) + theI=(theIPrev%l)+l; + prob1*=net->nodeProb(theI,theJ); + if( j==1 ) + { + prob2*=net->getAlphainit(theI); + } + else + { + prob2*=net->outProb(theJ,theIPrev,theI); + } + theIPrev=theI; + if( j==m ) + { + prob2*=net->getBetainit(theI); + } + } + d.push_back(prob1); + d.push_back(prob2); + } + + bool isSubOptimal()const{return 0;} +}; +#endif |