void SoftMatchingFeature::EvaluateWhenApplied(const ChartHypothesis& hypo,
ScoreComponentCollection* accumulator) const
{
const TargetPhrase& target = hypo.GetCurrTargetPhrase();
const AlignmentInfo::NonTermIndexMap &nonTermIndexMap = target.GetAlignNonTerm().GetNonTermIndexMap();
// loop over the rule that is being applied
for (size_t pos = 0; pos < target.GetSize(); ++pos) {
const Word& word = target.GetWord(pos);
// for non-terminals, trigger the feature mapping the LHS of the previous hypo to the RHS of this hypo
if (word.IsNonTerminal()) {
size_t nonTermInd = nonTermIndexMap[pos];
const ChartHypothesis* prevHypo = hypo.GetPrevHypo(nonTermInd);
const Word& prevLHS = prevHypo->GetTargetLHS();
if ( (word != prevLHS) || m_scoreIdentical ) {
const std::string &name = GetOrSetFeatureName(word, prevLHS);
accumulator->PlusEquals(this,name,1);
}
}
}
}
void SparseHieroReorderingFeature::EvaluateChart(
const ChartHypothesis& cur_hypo ,
ScoreComponentCollection* accumulator) const
{
// get index map for underlying hypotheses
//const AlignmentInfo::NonTermIndexMap &nonTermIndexMap =
// cur_hypo.GetCurrTargetPhrase().GetAlignNonTerm().GetNonTermIndexMap();
//The Huck features. For a rule with source side:
// abXcdXef
//We first have to split into blocks:
// ab X cd X ef
//Then we extract features based in the boundary words of the neighbouring blocks
//For the block pair, we use the right word of the left block, and the left
//word of the right block.
//Need to get blocks, and their alignment. Each block has a word range (on the
// on the source), a non-terminal flag, and a set of alignment points in the target phrase
//We need to be able to map source word position to target word position, as
//much as possible (don't need interior of non-terminals). The alignment info
//objects just give us the mappings between *rule* positions. So if we can
//map source word position to source rule position, and target rule position
//to target word position, then we can map right through.
size_t sourceStart = cur_hypo.GetCurrSourceRange().GetStartPos();
size_t sourceSize = cur_hypo.GetCurrSourceRange().GetNumWordsCovered();
vector<WordsRange> sourceNTSpans;
for (size_t prevHypoId = 0; prevHypoId < cur_hypo.GetPrevHypos().size(); ++prevHypoId) {
sourceNTSpans.push_back(cur_hypo.GetPrevHypo(prevHypoId)->GetCurrSourceRange());
}
//put in source order. Is this necessary?
sort(sourceNTSpans.begin(), sourceNTSpans.end());
//cerr << "Source NTs: ";
//for (size_t i = 0; i < sourceNTSpans.size(); ++i) cerr << sourceNTSpans[i] << " ";
//cerr << endl;
typedef pair<WordsRange,bool> Block;//flag indicates NT
vector<Block> sourceBlocks;
sourceBlocks.push_back(Block(cur_hypo.GetCurrSourceRange(),false));
for (vector<WordsRange>::const_iterator i = sourceNTSpans.begin();
i != sourceNTSpans.end(); ++i) {
const WordsRange& prevHypoRange = *i;
Block lastBlock = sourceBlocks.back();
sourceBlocks.pop_back();
//split this range into before NT, NT and after NT
if (prevHypoRange.GetStartPos() > lastBlock.first.GetStartPos()) {
sourceBlocks.push_back(Block(WordsRange(lastBlock.first.GetStartPos(),prevHypoRange.GetStartPos()-1),false));
}
sourceBlocks.push_back(Block(prevHypoRange,true));
if (prevHypoRange.GetEndPos() < lastBlock.first.GetEndPos()) {
sourceBlocks.push_back(Block(WordsRange(prevHypoRange.GetEndPos()+1,lastBlock.first.GetEndPos()), false));
}
}
/*
cerr << "Source Blocks: ";
for (size_t i = 0; i < sourceBlocks.size(); ++i) cerr << sourceBlocks[i].first << " "
<< (sourceBlocks[i].second ? "NT" : "T") << " ";
cerr << endl;
*/
//Mapping from source word to target rule position
vector<size_t> sourceWordToTargetRulePos(sourceSize);
map<size_t,size_t> alignMap;
alignMap.insert(
cur_hypo.GetCurrTargetPhrase().GetAlignTerm().begin(),
cur_hypo.GetCurrTargetPhrase().GetAlignTerm().end());
alignMap.insert(
cur_hypo.GetCurrTargetPhrase().GetAlignNonTerm().begin(),
cur_hypo.GetCurrTargetPhrase().GetAlignNonTerm().end());
//vector<size_t> alignMapTerm = cur_hypo.GetCurrTargetPhrase().GetAlignNonTerm()
size_t sourceRulePos = 0;
//cerr << "SW->RP ";
for (vector<Block>::const_iterator sourceBlockIt = sourceBlocks.begin();
sourceBlockIt != sourceBlocks.end(); ++sourceBlockIt) {
for (size_t sourceWordPos = sourceBlockIt->first.GetStartPos();
sourceWordPos <= sourceBlockIt->first.GetEndPos(); ++sourceWordPos) {
sourceWordToTargetRulePos[sourceWordPos - sourceStart] = alignMap[sourceRulePos];
// cerr << sourceWordPos - sourceStart << "-" << alignMap[sourceRulePos] << " ";
if (! sourceBlockIt->second) {
//T
++sourceRulePos;
}
}
if ( sourceBlockIt->second) {
//NT
++sourceRulePos;
}
}
//cerr << endl;
//Iterate through block pairs
const Sentence& sentence =
dynamic_cast<const Sentence&>(cur_hypo.GetManager().GetSource());
//const TargetPhrase& targetPhrase = cur_hypo.GetCurrTargetPhrase();
for (size_t i = 0; i < sourceBlocks.size()-1; ++i) {
Block& leftSourceBlock = sourceBlocks[i];
Block& rightSourceBlock = sourceBlocks[i+1];
size_t sourceLeftBoundaryPos = leftSourceBlock.first.GetEndPos();
size_t sourceRightBoundaryPos = rightSourceBlock.first.GetStartPos();
const Word& sourceLeftBoundaryWord = sentence.GetWord(sourceLeftBoundaryPos);
const Word& sourceRightBoundaryWord = sentence.GetWord(sourceRightBoundaryPos);
sourceLeftBoundaryPos -= sourceStart;
sourceRightBoundaryPos -= sourceStart;
// Need to figure out where these map to on the target.
size_t targetLeftRulePos =
sourceWordToTargetRulePos[sourceLeftBoundaryPos];
size_t targetRightRulePos =
sourceWordToTargetRulePos[sourceRightBoundaryPos];
bool isMonotone = true;
if ((sourceLeftBoundaryPos < sourceRightBoundaryPos &&
targetLeftRulePos > targetRightRulePos) ||
((sourceLeftBoundaryPos > sourceRightBoundaryPos &&
targetLeftRulePos < targetRightRulePos)))
{
isMonotone = false;
}
stringstream buf;
buf << "h_"; //sparse reordering, Huck
if (m_type == SourceLeft || m_type == SourceCombined) {
buf << GetFactor(sourceLeftBoundaryWord,m_sourceVocab,m_sourceFactor)->GetString();
buf << "_";
}
if (m_type == SourceRight || m_type == SourceCombined) {
buf << GetFactor(sourceRightBoundaryWord,m_sourceVocab,m_sourceFactor)->GetString();
buf << "_";
}
buf << (isMonotone ? "M" : "S");
accumulator->PlusEquals(this,buf.str(), 1);
}
// cerr << endl;
}
