mosesdecoder/moses/TranslationModel/UG/sapt_pscore_rareness.h

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// -*- c++ -*-
// Phrase scorer that rewards the number of phrase pair occurrences in a bitext
// with the asymptotic function x/(j+x) where x > 0 is a function
// parameter that determines the steepness of the rewards curve
// written by Ulrich Germann
#include "sapt_pscore_base.h"
#include <boost/dynamic_bitset.hpp>
using namespace std;
namespace Moses {
namespace bitext {
// rareness penalty: x/(n+x)
template<typename Token>
class
PScoreRareness : public SingleRealValuedParameterPhraseScorerFamily<Token>
{
public:
PScoreRareness(string const spec)
{
this->m_tag = "rare";
this->init(spec);
}
bool
isLogVal(int i) const { return false; }
void
operator()(Bitext<Token> const& bt,
PhrasePair<Token>& pp,
vector<float> * dest = NULL) const
{
if (!dest) dest = &pp.fvals;
size_t i = this->m_index;
BOOST_FOREACH(float const x, this->m_x)
(*dest).at(i++) = x/(x + pp.joint);
}
};
} // namespace bitext
} // namespace Moses