mosesdecoder/moses/PP/NonTermContextProperty.cpp

#include "moses/PP/NonTermContextProperty.h"
#include <string>
#include <cassert>
#include "moses/Util.h"
#include "moses/FactorCollection.h"

using namespace std;

namespace Moses
{
NonTermContextProperty::NonTermContextProperty()
{
}

NonTermContextProperty::~NonTermContextProperty()
{
  //RemoveAllInColl(m_probStores);
}

void NonTermContextProperty::ProcessValue(const std::string &value)
{
  vector<string> toks;
  Tokenize(toks, value);

  FactorCollection &fc = FactorCollection::Instance();

  size_t numNT = Scan<size_t>(toks[0]);
  m_probStores.resize(numNT);

  size_t ind = 1;
  while (ind < toks.size()) {
    vector<const Factor *> factors;

    for (size_t nt = 0; nt < numNT; ++nt) {
      size_t ntInd = Scan<size_t>(toks[ind]);
      assert(nt == ntInd);
      ++ind;

      for (size_t contextInd = 0; contextInd < 4; ++contextInd) {
        //cerr << "toks[" << ind << "]=" << toks[ind] << endl;
        const Factor *factor = fc.AddFactor(toks[ind], false);
        factors.push_back(factor);
        ++ind;
      }
    }

    // done with the context. Just get the count and put it all into data structures
    // cerr << "count=" << toks[ind] << endl;
    float count = Scan<float>(toks[ind]);
    ++ind;

    for (size_t i = 0; i < factors.size(); ++i) {
      size_t ntInd = i / 4;
      size_t contextInd = i % 4;
      const Factor *factor = factors[i];
      AddToMap(ntInd, contextInd, factor, count);
    }
  }
}

void NonTermContextProperty::AddToMap(size_t ntIndex, size_t index, const Factor *factor, float count)
{
  if (ntIndex <= m_probStores.size()) {
    m_probStores.resize(ntIndex + 1);
  }

  ProbStore &probStore = m_probStores[ntIndex];
  probStore.AddToMap(index, factor, count);
}

float NonTermContextProperty::GetProb(size_t ntInd,
                                      size_t contextInd,
                                      const Factor *factor,
                                      float smoothConstant) const
{
  UTIL_THROW_IF2(ntInd >= m_probStores.size(), "Invalid nt index=" << ntInd);
  const ProbStore &probStore = m_probStores[ntInd];
  float ret = probStore.GetProb(contextInd, factor, smoothConstant);
  return ret;
}

//////////////////////////////////////////

void NonTermContextProperty::ProbStore::AddToMap(size_t index, const Factor *factor, float count)
{
  Map &map = m_vec[index];

  Map::iterator iter = map.find(factor);
  if (iter == map.end()) {
    map[factor] = count;
  } else {
    float &currCount = iter->second;
    currCount += count;
  }

  m_totalCount += count;
}


float NonTermContextProperty::ProbStore::GetProb(size_t contextInd,
    const Factor *factor,
    float smoothConstant) const
{
  float count = GetCount(contextInd, factor, smoothConstant);
  float total = GetTotalCount(contextInd, smoothConstant);
  float ret = count / total;
  return ret;
}

float NonTermContextProperty::ProbStore::GetCount(size_t contextInd,
    const Factor *factor,
    float smoothConstant) const
{
  const Map &map = m_vec[contextInd];

  float count = smoothConstant;
  Map::const_iterator iter = map.find(factor);
  if (iter == map.end()) {
    // nothing
  } else {
    count += iter->second;
  }

  return count;
}

float NonTermContextProperty::ProbStore::GetTotalCount(size_t contextInd, float smoothConstant) const
{
  const Map &map = m_vec[contextInd];
  return m_totalCount + smoothConstant * map.size();
}


} // namespace Moses