mirror of
https://github.com/moses-smt/mosesdecoder.git
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c165e80e48
- added phrase table features: pfwd / pbwd weighted by each sample's weight (when used with biased sampling) - a few minor internal changes ({p|j}stats.add(...) reports back current joint count (intended for early stopping of sampling when evidence is sufficient; yet to be explored experimentally).
62 lines
1.7 KiB
C++
62 lines
1.7 KiB
C++
//-*- c++ -*-
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// written by Ulrich Germann
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#pragma once
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#include "moses/TranslationModel/UG/mm/ug_bitext.h"
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#include "util/exception.hh"
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#include "boost/format.hpp"
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#include "boost/foreach.hpp"
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namespace sapt
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{
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template<typename Token>
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class
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PScorePbwd : public PhraseScorer<Token>
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{
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float conf;
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std::string denom;
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public:
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virtual ~PScorePbwd(){};
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PScorePbwd(float const c, std::string d)
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{
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this->m_index = -1;
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conf = c;
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denom = d;
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size_t checksum = d.size();
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BOOST_FOREACH(char const& x, denom)
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{
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if (x == '+') { --checksum; continue; }
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if (x != 'g' && x != 's' && x != 'r' && x != 'b') continue;
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std::string s = (boost::format("pbwd-%c%.3f") % x % c).str();
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this->m_feature_names.push_back(s);
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}
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this->m_num_feats = this->m_feature_names.size();
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UTIL_THROW_IF2(this->m_feature_names.size() != checksum,
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"Unknown parameter in specification '"
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<< d << "' for Pbwd phrase scorer at " << HERE);
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}
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void
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operator()(Bitext<Token> const& bt,
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PhrasePair<Token>& pp,
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std::vector<float> * dest = NULL) const
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{
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if (!dest) dest = &pp.fvals;
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// we use the denominator specification to scale the raw counts on the
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// target side; the clean way would be to counter-sample
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size_t i = this->m_index;
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BOOST_FOREACH(char const& x, denom)
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{
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uint32_t m2 = pp.raw2;
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if (x == 'g' || x == 'b') m2 = round(m2 * float(pp.good1) / pp.raw1);
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else if (x == 's') m2 = round(m2 * float(pp.sample1) / pp.raw1);
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(*dest)[i] = log(lbop(std::max(m2, pp.joint), pp.joint,conf));
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if (x == 'b') (*dest)[i] += log(pp.cum_bias) - log(pp.joint);
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++i;
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}
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}
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};
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} // namespace sapt
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