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authorChris Dyer <redpony@gmail.com>2010-02-18 17:06:59 -0500
committerChris Dyer <redpony@gmail.com>2010-02-18 17:06:59 -0500
commit4d47dbd7da0434de67ac619392d516c678e1f2ca (patch)
treefdb327696aa30e79983602c0e7d5fde372efbde5 /training/mr_em_train.cc
parentc97b8a8b58f7385fb48b74e2cf1ea9610cd1202f (diff)
add generative word alignment model and primitive EM trainer. Model 1 and HMM are supported, without NULL source words
Diffstat (limited to 'training/mr_em_train.cc')
-rw-r--r--training/mr_em_train.cc270
1 files changed, 0 insertions, 270 deletions
diff --git a/training/mr_em_train.cc b/training/mr_em_train.cc
deleted file mode 100644
index a15fbe4c..00000000
--- a/training/mr_em_train.cc
+++ /dev/null
@@ -1,270 +0,0 @@
-#include <iostream>
-#include <vector>
-#include <cassert>
-#include <cmath>
-
-#include <boost/program_options.hpp>
-#include <boost/program_options/variables_map.hpp>
-
-#include "config.h"
-#ifdef HAVE_BOOST_DIGAMMA
-#include <boost/math/special_functions/digamma.hpp>
-using boost::math::digamma;
-#endif
-
-#include "tdict.h"
-#include "filelib.h"
-#include "trule.h"
-#include "fdict.h"
-#include "weights.h"
-#include "sparse_vector.h"
-
-using namespace std;
-using boost::shared_ptr;
-namespace po = boost::program_options;
-
-#ifndef HAVE_BOOST_DIGAMMA
-#warning Using Mark Johnson's digamma()
-double digamma(double x) {
- double result = 0, xx, xx2, xx4;
- assert(x > 0);
- for ( ; x < 7; ++x)
- result -= 1/x;
- x -= 1.0/2.0;
- xx = 1.0/x;
- xx2 = xx*xx;
- xx4 = xx2*xx2;
- result += log(x)+(1./24.)*xx2-(7.0/960.0)*xx4+(31.0/8064.0)*xx4*xx2-(127.0/30720.0)*xx4*xx4;
- return result;
-}
-#endif
-
-void SanityCheck(const vector<double>& w) {
- for (int i = 0; i < w.size(); ++i) {
- assert(!isnan(w[i]));
- }
-}
-
-struct FComp {
- const vector<double>& w_;
- FComp(const vector<double>& w) : w_(w) {}
- bool operator()(int a, int b) const {
- return w_[a] > w_[b];
- }
-};
-
-void ShowLargestFeatures(const vector<double>& w) {
- vector<int> fnums(w.size() - 1);
- for (int i = 1; i < w.size(); ++i)
- fnums[i-1] = i;
- vector<int>::iterator mid = fnums.begin();
- mid += (w.size() > 10 ? 10 : w.size()) - 1;
- partial_sort(fnums.begin(), mid, fnums.end(), FComp(w));
- cerr << "MOST PROBABLE:";
- for (vector<int>::iterator i = fnums.begin(); i != mid; ++i) {
- cerr << ' ' << FD::Convert(*i) << '=' << w[*i];
- }
- cerr << endl;
-}
-
-void InitCommandLine(int argc, char** argv, po::variables_map* conf) {
- po::options_description opts("Configuration options");
- opts.add_options()
- ("output,o",po::value<string>()->default_value("-"),"Output log probs file")
- ("grammar,g",po::value<vector<string> >()->composing(),"SCFG grammar file(s)")
- ("optimization_method,m", po::value<string>()->default_value("em"), "Optimization method (em, vb)")
- ("input_format,f",po::value<string>()->default_value("b64"),"Encoding of the input (b64 or text)");
- po::options_description clo("Command line options");
- clo.add_options()
- ("config", po::value<string>(), "Configuration file")
- ("help,h", "Print this help message and exit");
- po::options_description dconfig_options, dcmdline_options;
- dconfig_options.add(opts);
- dcmdline_options.add(opts).add(clo);
-
- po::store(parse_command_line(argc, argv, dcmdline_options), *conf);
- if (conf->count("config")) {
- ifstream config((*conf)["config"].as<string>().c_str());
- po::store(po::parse_config_file(config, dconfig_options), *conf);
- }
- po::notify(*conf);
-
- if (conf->count("help") || !conf->count("grammar")) {
- cerr << dcmdline_options << endl;
- exit(1);
- }
-}
-
-// describes a multinomial or multinomial with a prior
-// does not contain the parameters- just the list of events
-// and any hyperparameters
-struct MultinomialInfo {
- MultinomialInfo() : alpha(1.0) {}
- vector<int> events; // the events that this multinomial generates
- double alpha; // hyperparameter for (optional) Dirichlet prior
-};
-
-typedef map<WordID, MultinomialInfo> ModelDefinition;
-
-void LoadModelEvents(const po::variables_map& conf, ModelDefinition* pm) {
- ModelDefinition& m = *pm;
- m.clear();
- vector<string> gfiles = conf["grammar"].as<vector<string> >();
- for (int i = 0; i < gfiles.size(); ++i) {
- ReadFile rf(gfiles[i]);
- istream& in = *rf.stream();
- int lc = 0;
- while(in) {
- string line;
- getline(in, line);
- if (line.empty()) continue;
- ++lc;
- TRule r(line, true);
- const SparseVector<double>& f = r.GetFeatureValues();
- if (f.num_active() == 0) {
- cerr << "[WARNING] no feature found in " << gfiles[i] << ':' << lc << endl;
- continue;
- }
- if (f.num_active() > 1) {
- cerr << "[ERROR] more than one feature found in " << gfiles[i] << ':' << lc << endl;
- exit(1);
- }
- SparseVector<double>::const_iterator it = f.begin();
- if (it->second != 1.0) {
- cerr << "[ERROR] feature with value != 1 found in " << gfiles[i] << ':' << lc << endl;
- exit(1);
- }
- m[r.GetLHS()].events.push_back(it->first);
- }
- }
- for (ModelDefinition::iterator it = m.begin(); it != m.end(); ++it) {
- const vector<int>& v = it->second.events;
- cerr << "Multinomial [" << TD::Convert(it->first*-1) << "]\n";
- if (v.size() < 1000) {
- cerr << " generates:";
- for (int i = 0; i < v.size(); ++i) {
- cerr << " " << FD::Convert(v[i]);
- }
- cerr << endl;
- }
- }
-}
-
-void Maximize(const ModelDefinition& m, const bool use_vb, vector<double>* counts) {
- for (ModelDefinition::const_iterator it = m.begin(); it != m.end(); ++it) {
- const MultinomialInfo& mult_info = it->second;
- const vector<int>& events = mult_info.events;
- cerr << "Multinomial [" << TD::Convert(it->first*-1) << "]";
- double tot = 0;
- for (int i = 0; i < events.size(); ++i)
- tot += (*counts)[events[i]];
- cerr << " = " << tot << endl;
- assert(tot > 0.0);
- double ltot = log(tot);
- if (use_vb)
- ltot = digamma(tot + events.size() * mult_info.alpha);
- for (int i = 0; i < events.size(); ++i) {
- if (use_vb) {
- (*counts)[events[i]] = digamma((*counts)[events[i]] + mult_info.alpha) - ltot;
- } else {
- (*counts)[events[i]] = log((*counts)[events[i]]) - ltot;
- }
- }
- if (events.size() < 50) {
- for (int i = 0; i < events.size(); ++i) {
- cerr << " p(" << FD::Convert(events[i]) << ")=" << exp((*counts)[events[i]]);
- }
- cerr << endl;
- }
- }
-}
-
-int main(int argc, char** argv) {
- po::variables_map conf;
- InitCommandLine(argc, argv, &conf);
-
- const bool use_b64 = conf["input_format"].as<string>() == "b64";
- const bool use_vb = conf["optimization_method"].as<string>() == "vb";
- if (use_vb)
- cerr << "Using variational Bayes, make sure alphas are set\n";
-
- ModelDefinition model_def;
- LoadModelEvents(conf, &model_def);
-
- const string s_obj = "**OBJ**";
- int num_feats = FD::NumFeats();
- cerr << "Number of features: " << num_feats << endl;
-
- vector<double> counts(num_feats, 0);
- double logprob = 0;
- // 0<TAB>**OBJ**=12.2;Feat1=2.3;Feat2=-0.2;
- // 0<TAB>**OBJ**=1.1;Feat1=1.0;
-
- // E-step
- while(cin) {
- string line;
- getline(cin, line);
- if (line.empty()) continue;
- int feat;
- double val;
- size_t i = line.find("\t");
- assert(i != string::npos);
- ++i;
- if (use_b64) {
- SparseVector<double> g;
- double obj;
- if (!B64::Decode(&obj, &g, &line[i], line.size() - i)) {
- cerr << "B64 decoder returned error, skipping!\n";
- continue;
- }
- logprob += obj;
- const SparseVector<double>& cg = g;
- for (SparseVector<double>::const_iterator it = cg.begin(); it != cg.end(); ++it) {
- if (it->first >= num_feats) {
- cerr << "Unexpected feature: " << FD::Convert(it->first) << endl;
- abort();
- }
- counts[it->first] += it->second;
- }
- } else { // text encoding - your counts will not be accurate!
- while (i < line.size()) {
- size_t start = i;
- while (line[i] != '=' && i < line.size()) ++i;
- if (i == line.size()) { cerr << "FORMAT ERROR\n"; break; }
- string fname = line.substr(start, i - start);
- if (fname == s_obj) {
- feat = -1;
- } else {
- feat = FD::Convert(line.substr(start, i - start));
- if (feat >= num_feats) {
- cerr << "Unexpected feature: " << line.substr(start, i - start) << endl;
- abort();
- }
- }
- ++i;
- start = i;
- while (line[i] != ';' && i < line.size()) ++i;
- if (i - start == 0) continue;
- val = atof(line.substr(start, i - start).c_str());
- ++i;
- if (feat == -1) {
- logprob += val;
- } else {
- counts[feat] += val;
- }
- }
- }
- }
-
- cerr << "LOGPROB: " << logprob << endl;
- // M-step
- Maximize(model_def, use_vb, &counts);
-
- SanityCheck(counts);
- ShowLargestFeatures(counts);
- Weights weights;
- weights.InitFromVector(counts);
- weights.WriteToFile(conf["output"].as<string>(), false);
-
- return 0;
-}