mosesdecoder/mert/HopeFearDecoder.cpp
Rico Sennrich 3d00e5dc8c basic support for more metrics with kbmira
metrics need getReferenceLength (for background smoothing) to work with kbmira
2014-09-22 10:49:20 +01:00

344 lines
12 KiB
C++

/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2014- University of Edinburgh
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
***********************************************************************/
#include <algorithm>
#include <cmath>
#include <iterator>
#define BOOST_FILESYSTEM_VERSION 3
#include <boost/filesystem.hpp>
#include <boost/lexical_cast.hpp>
#include "util/exception.hh"
#include "util/file_piece.hh"
#include "Scorer.h"
#include "HopeFearDecoder.h"
using namespace std;
namespace fs = boost::filesystem;
namespace MosesTuning {
static const ValType BLEU_RATIO = 5;
ValType HopeFearDecoder::Evaluate(const AvgWeightVector& wv) {
vector<ValType> stats(scorer_->NumberOfScores(),0);
for(reset(); !finished(); next()) {
vector<ValType> sent;
MaxModel(wv,&sent);
for(size_t i=0; i<sent.size(); i++) {
stats[i]+=sent[i];
}
}
return scorer_->calculateScore(stats);
}
NbestHopeFearDecoder::NbestHopeFearDecoder(
const vector<string>& featureFiles,
const vector<string>& scoreFiles,
bool streaming,
bool no_shuffle,
bool safe_hope,
Scorer* scorer
) : safe_hope_(safe_hope) {
scorer_ = scorer;
if (streaming) {
train_.reset(new StreamingHypPackEnumerator(featureFiles, scoreFiles));
} else {
train_.reset(new RandomAccessHypPackEnumerator(featureFiles, scoreFiles, no_shuffle));
}
}
void NbestHopeFearDecoder::next() {
train_->next();
}
bool NbestHopeFearDecoder::finished() {
return train_->finished();
}
void NbestHopeFearDecoder::reset() {
train_->reset();
}
void NbestHopeFearDecoder::HopeFear(
const std::vector<ValType>& backgroundBleu,
const MiraWeightVector& wv,
HopeFearData* hopeFear
) {
// Hope / fear decode
ValType hope_scale = 1.0;
size_t hope_index=0, fear_index=0, model_index=0;
ValType hope_score=0, fear_score=0, model_score=0;
for(size_t safe_loop=0; safe_loop<2; safe_loop++) {
ValType hope_bleu, hope_model;
for(size_t i=0; i< train_->cur_size(); i++) {
const MiraFeatureVector& vec=train_->featuresAt(i);
ValType score = wv.score(vec);
ValType bleu = scorer_->calculateSentenceLevelBackgroundScore(train_->scoresAt(i),backgroundBleu);
// Hope
if(i==0 || (hope_scale*score + bleu) > hope_score) {
hope_score = hope_scale*score + bleu;
hope_index = i;
hope_bleu = bleu;
hope_model = score;
}
// Fear
if(i==0 || (score - bleu) > fear_score) {
fear_score = score - bleu;
fear_index = i;
}
// Model
if(i==0 || score > model_score) {
model_score = score;
model_index = i;
}
}
// Outer loop rescales the contribution of model score to 'hope' in antagonistic cases
// where model score is having far more influence than BLEU
hope_bleu *= BLEU_RATIO; // We only care about cases where model has MUCH more influence than BLEU
if(safe_hope_ && safe_loop==0 && abs(hope_model)>1e-8 && abs(hope_bleu)/abs(hope_model)<hope_scale)
hope_scale = abs(hope_bleu) / abs(hope_model);
else break;
}
hopeFear->modelFeatures = train_->featuresAt(model_index);
hopeFear->hopeFeatures = train_->featuresAt(hope_index);
hopeFear->fearFeatures = train_->featuresAt(fear_index);
hopeFear->hopeStats = train_->scoresAt(hope_index);
hopeFear->hopeBleu = scorer_->calculateSentenceLevelBackgroundScore(hopeFear->hopeStats, backgroundBleu);
const vector<float>& fear_stats = train_->scoresAt(fear_index);
hopeFear->fearBleu = scorer_->calculateSentenceLevelBackgroundScore(fear_stats, backgroundBleu);
hopeFear->modelStats = train_->scoresAt(model_index);
hopeFear->hopeFearEqual = (hope_index == fear_index);
}
void NbestHopeFearDecoder::MaxModel(const AvgWeightVector& wv, std::vector<ValType>* stats) {
// Find max model
size_t max_index=0;
ValType max_score=0;
for(size_t i=0; i<train_->cur_size(); i++) {
MiraFeatureVector vec(train_->featuresAt(i));
ValType score = wv.score(vec);
if(i==0 || score > max_score) {
max_index = i;
max_score = score;
}
}
*stats = train_->scoresAt(max_index);
}
HypergraphHopeFearDecoder::HypergraphHopeFearDecoder
(
const string& hypergraphDir,
const vector<string>& referenceFiles,
size_t num_dense,
bool streaming,
bool no_shuffle,
bool safe_hope,
size_t hg_pruning,
const MiraWeightVector& wv,
Scorer* scorer
) :
num_dense_(num_dense) {
UTIL_THROW_IF(streaming, util::Exception, "Streaming not currently supported for hypergraphs");
UTIL_THROW_IF(!fs::exists(hypergraphDir), HypergraphException, "Directory '" << hypergraphDir << "' does not exist");
UTIL_THROW_IF(!referenceFiles.size(), util::Exception, "No reference files supplied");
references_.Load(referenceFiles, vocab_);
SparseVector weights;
wv.ToSparse(&weights);
scorer_ = scorer;
static const string kWeights = "weights";
fs::directory_iterator dend;
size_t fileCount = 0;
cerr << "Reading hypergraphs" << endl;
for (fs::directory_iterator di(hypergraphDir); di != dend; ++di) {
const fs::path& hgpath = di->path();
if (hgpath.filename() == kWeights) continue;
Graph graph(vocab_);
size_t id = boost::lexical_cast<size_t>(hgpath.stem().string());
util::scoped_fd fd(util::OpenReadOrThrow(hgpath.string().c_str()));
//util::FilePiece file(di->path().string().c_str());
util::FilePiece file(fd.release());
ReadGraph(file,graph);
//cerr << "ref length " << references_.Length(id) << endl;
size_t edgeCount = hg_pruning * references_.Length(id);
boost::shared_ptr<Graph> prunedGraph;
prunedGraph.reset(new Graph(vocab_));
graph.Prune(prunedGraph.get(), weights, edgeCount);
graphs_[id] = prunedGraph;
//cerr << "Pruning to v=" << graphs_[id]->VertexSize() << " e=" << graphs_[id]->EdgeSize() << endl;
++fileCount;
if (fileCount % 10 == 0) cerr << ".";
if (fileCount % 400 == 0) cerr << " [count=" << fileCount << "]\n";
}
cerr << endl << "Done" << endl;
sentenceIds_.resize(graphs_.size());
for (size_t i = 0; i < graphs_.size(); ++i) sentenceIds_[i] = i;
if (!no_shuffle) {
random_shuffle(sentenceIds_.begin(), sentenceIds_.end());
}
}
void HypergraphHopeFearDecoder::reset() {
sentenceIdIter_ = sentenceIds_.begin();
}
void HypergraphHopeFearDecoder::next() {
sentenceIdIter_++;
}
bool HypergraphHopeFearDecoder::finished() {
return sentenceIdIter_ == sentenceIds_.end();
}
void HypergraphHopeFearDecoder::HopeFear(
const vector<ValType>& backgroundBleu,
const MiraWeightVector& wv,
HopeFearData* hopeFear
) {
size_t sentenceId = *sentenceIdIter_;
SparseVector weights;
wv.ToSparse(&weights);
const Graph& graph = *(graphs_[sentenceId]);
ValType hope_scale = 1.0;
HgHypothesis hopeHypo, fearHypo, modelHypo;
for(size_t safe_loop=0; safe_loop<2; safe_loop++) {
//hope decode
Viterbi(graph, weights, 1, references_, sentenceId, backgroundBleu, &hopeHypo);
//fear decode
Viterbi(graph, weights, -1, references_, sentenceId, backgroundBleu, &fearHypo);
//Model decode
Viterbi(graph, weights, 0, references_, sentenceId, backgroundBleu, &modelHypo);
// Outer loop rescales the contribution of model score to 'hope' in antagonistic cases
// where model score is having far more influence than BLEU
// hope_bleu *= BLEU_RATIO; // We only care about cases where model has MUCH more influence than BLEU
// if(safe_hope_ && safe_loop==0 && abs(hope_model)>1e-8 && abs(hope_bleu)/abs(hope_model)<hope_scale)
// hope_scale = abs(hope_bleu) / abs(hope_model);
// else break;
//TODO: Don't currently get model and bleu so commented this out for now.
break;
}
//modelFeatures, hopeFeatures and fearFeatures
hopeFear->modelFeatures = MiraFeatureVector(modelHypo.featureVector, num_dense_);
hopeFear->hopeFeatures = MiraFeatureVector(hopeHypo.featureVector, num_dense_);
hopeFear->fearFeatures = MiraFeatureVector(fearHypo.featureVector, num_dense_);
//Need to know which are to be mapped to dense features!
//Only C++11
//hopeFear->modelStats.assign(std::begin(modelHypo.bleuStats), std::end(modelHypo.bleuStats));
vector<ValType> fearStats(scorer_->NumberOfScores());
hopeFear->hopeStats.reserve(scorer_->NumberOfScores());
hopeFear->modelStats.reserve(scorer_->NumberOfScores());
for (size_t i = 0; i < fearStats.size(); ++i) {
hopeFear->modelStats.push_back(modelHypo.bleuStats[i]);
hopeFear->hopeStats.push_back(hopeHypo.bleuStats[i]);
fearStats[i] = fearHypo.bleuStats[i];
}
/*
cerr << "hope" << endl;;
for (size_t i = 0; i < hopeHypo.text.size(); ++i) {
cerr << hopeHypo.text[i]->first << " ";
}
cerr << endl;
for (size_t i = 0; i < fearStats.size(); ++i) {
cerr << hopeHypo.bleuStats[i] << " ";
}
cerr << endl;
cerr << "fear";
for (size_t i = 0; i < fearHypo.text.size(); ++i) {
cerr << fearHypo.text[i]->first << " ";
}
cerr << endl;
for (size_t i = 0; i < fearStats.size(); ++i) {
cerr << fearHypo.bleuStats[i] << " ";
}
cerr << endl;
cerr << "model";
for (size_t i = 0; i < modelHypo.text.size(); ++i) {
cerr << modelHypo.text[i]->first << " ";
}
cerr << endl;
for (size_t i = 0; i < fearStats.size(); ++i) {
cerr << modelHypo.bleuStats[i] << " ";
}
cerr << endl;
*/
hopeFear->hopeBleu = sentenceLevelBackgroundBleu(hopeFear->hopeStats, backgroundBleu);
hopeFear->fearBleu = sentenceLevelBackgroundBleu(fearStats, backgroundBleu);
//If fv and bleu stats are equal, then assume equal
hopeFear->hopeFearEqual = true; //(hopeFear->hopeBleu - hopeFear->fearBleu) >= 1e-8;
if (hopeFear->hopeFearEqual) {
for (size_t i = 0; i < fearStats.size(); ++i) {
if (fearStats[i] != hopeFear->hopeStats[i]) {
hopeFear->hopeFearEqual = false;
break;
}
}
}
hopeFear->hopeFearEqual = hopeFear->hopeFearEqual && (hopeFear->fearFeatures == hopeFear->hopeFeatures);
}
void HypergraphHopeFearDecoder::MaxModel(const AvgWeightVector& wv, vector<ValType>* stats) {
assert(!finished());
HgHypothesis bestHypo;
size_t sentenceId = *sentenceIdIter_;
SparseVector weights;
wv.ToSparse(&weights);
vector<ValType> bg(scorer_->NumberOfScores());
Viterbi(*(graphs_[sentenceId]), weights, 0, references_, sentenceId, bg, &bestHypo);
stats->resize(bestHypo.bleuStats.size());
/*
for (size_t i = 0; i < bestHypo.text.size(); ++i) {
cerr << bestHypo.text[i]->first << " ";
}
cerr << endl;
*/
for (size_t i = 0; i < bestHypo.bleuStats.size(); ++i) {
(*stats)[i] = bestHypo.bleuStats[i];
}
}
};