mosesdecoder/moses/TranslationModel/UG/sapt_pscore_pfwd.h

// -*- c++ -*-
// written by Ulrich Germann
#pragma once
#include "moses/TranslationModel/UG/mm/ug_bitext.h"
#include "util/exception.hh"
#include "boost/format.hpp"
#include "boost/foreach.hpp"

namespace sapt
{
  template<typename Token>
  class
  PScorePfwd : public PhraseScorer<Token>
  {
    float   conf;
    std::string denom;

  public:

    virtual ~PScorePfwd(){};
    PScorePfwd(float const c, std::string d)
    {
      this->m_index = -1;
      conf  = c;
      denom = d;
      size_t checksum = d.size();
      BOOST_FOREACH(char const& x, denom)
	{
	  if (x == '+') { --checksum; continue; }
	  if (x != 'g' && x != 's' && x != 'r' && x != 'b') continue;
	  std::string s = (boost::format("pfwd-%c%.3f") % x % c).str();
	  this->m_feature_names.push_back(s);
	}
      this->m_num_feats = this->m_feature_names.size();
      UTIL_THROW_IF2(this->m_feature_names.size() != checksum,
		     "Unknown parameter in specification '"
		     << d << "' for Pfwd phrase scorer at " << HERE);
    }

    void
    operator()(Bitext<Token> const& bt,
         PhrasePair<Token>& pp,
         std::vector<float> * dest = NULL) const
    {
      if (!dest) dest = &pp.fvals;
      if (pp.joint > pp.good1)
	{
	  pp.joint = pp.good1;
	  // cerr<<bt.toString(pp.p1,0)<<" ::: "<<bt.toString(pp.p2,1)<<endl;
	  // cerr<<pp.joint<<"/"<<pp.good1<<"/"<<pp.raw2<<endl;
	}
      size_t i = this->m_index;
      float g = log(lbop(pp.good1, pp.joint, conf));; 
      BOOST_FOREACH(char const& c, this->denom)
	{
	  switch (c)
	    {
	    case 'b':
	      (*dest)[i++] = g + log(pp.cum_bias) - log(pp.joint);
	      break;
	    case 'g':
	      (*dest)[i++] = g;
	      break;
	    case 's':
	      (*dest)[i++] = log(lbop(pp.sample1, pp.joint, conf));
	      break;
	    case 'r':
	      (*dest)[i++] = log(lbop(pp.raw1, pp.joint, conf));
	    }
	}
    }
  };
}