polish

4 files changed, 830 insertions, 0 deletions

diff --git a/dtrain/test/mtm11/mira_update/Hildreth.cpp b/dtrain/test/mtm11/mira_update/Hildreth.cpp
new file mode 100644
index 00000000..0e67eb15
--- /dev/null
+++ b/dtrain/test/mtm11/mira_update/Hildreth.cpp
@@ -0,0 +1,187 @@
+#include "Hildreth.h"
+#include "sparse_vector.h"
+
+using namespace std;
+
+namespace Mira {
+   vector<double> Hildreth::optimise (vector< SparseVector<double> >& a, vector<double>& b) {
+
+    size_t i;
+    int max_iter = 10000;
+    double eps = 0.00000001;
+    double zero = 0.000000000001;
+
+    vector<double> alpha ( b.size() );
+    vector<double> F ( b.size() );
+    vector<double> kkt ( b.size() );
+
+    double max_kkt = -1e100;
+
+    size_t K = b.size();
+
+    double A[K][K];
+    bool is_computed[K];
+    for ( i = 0; i < K; i++ )
+    {
+      A[i][i] = a[i].dot(a[i]);
+      is_computed[i] = false;
+    }
+
+    int max_kkt_i = -1;
+
+
+    for ( i = 0; i < b.size(); i++ )
+    {
+      F[i] = b[i];
+      kkt[i] = F[i];
+      if ( kkt[i] > max_kkt )
+      {
+        max_kkt = kkt[i];
+        max_kkt_i = i;
+      }
+    }
+
+    int iter = 0;
+    double diff_alpha;
+    double try_alpha;
+    double add_alpha;
+
+    while ( max_kkt >= eps && iter < max_iter )
+    {
+
+      diff_alpha = A[max_kkt_i][max_kkt_i] <= zero ? 0.0 : F[max_kkt_i]/A[max_kkt_i][max_kkt_i];
+      try_alpha = alpha[max_kkt_i] + diff_alpha;
+      add_alpha = 0.0;
+
+      if ( try_alpha < 0.0 )
+        add_alpha = -1.0 * alpha[max_kkt_i];
+      else
+        add_alpha = diff_alpha;
+
+      alpha[max_kkt_i] = alpha[max_kkt_i] + add_alpha;
+
+      if ( !is_computed[max_kkt_i] )
+      {
+        for ( i = 0; i < K; i++ )
+        {
+          A[i][max_kkt_i] = a[i].dot(a[max_kkt_i] ); // for version 1
+          //A[i][max_kkt_i] = 0; // for version 1
+          is_computed[max_kkt_i] = true;
+        }
+      }
+
+      for ( i = 0; i < F.size(); i++ )
+      {
+        F[i] -= add_alpha * A[i][max_kkt_i];
+        kkt[i] = F[i];
+        if ( alpha[i] > zero )
+          kkt[i] = abs ( F[i] );
+      }
+      max_kkt = -1e100;
+      max_kkt_i = -1;
+      for ( i = 0; i < F.size(); i++ )
+        if ( kkt[i] > max_kkt )
+        {
+          max_kkt = kkt[i];
+          max_kkt_i = i;
+        }
+
+      iter++;
+    }
+
+    return alpha;
+  }
+
+  vector<double> Hildreth::optimise (vector< SparseVector<double> >& a, vector<double>& b, double C) {
+
+    size_t i;
+    int max_iter = 10000;
+    double eps = 0.00000001;
+    double zero = 0.000000000001;
+
+    vector<double> alpha ( b.size() );
+    vector<double> F ( b.size() );
+    vector<double> kkt ( b.size() );
+
+    double max_kkt = -1e100;
+
+    size_t K = b.size();
+
+    double A[K][K];
+    bool is_computed[K];
+    for ( i = 0; i < K; i++ )
+    {
+      A[i][i] = a[i].dot(a[i]);
+      is_computed[i] = false;
+    }
+
+    int max_kkt_i = -1;
+
+
+    for ( i = 0; i < b.size(); i++ )
+    {
+      F[i] = b[i];
+      kkt[i] = F[i];
+      if ( kkt[i] > max_kkt )
+      {
+        max_kkt = kkt[i];
+        max_kkt_i = i;
+      }
+    }
+
+    int iter = 0;
+    double diff_alpha;
+    double try_alpha;
+    double add_alpha;
+
+    while ( max_kkt >= eps && iter < max_iter )
+    {
+
+      diff_alpha = A[max_kkt_i][max_kkt_i] <= zero ? 0.0 : F[max_kkt_i]/A[max_kkt_i][max_kkt_i];
+      try_alpha = alpha[max_kkt_i] + diff_alpha;
+      add_alpha = 0.0;
+
+      if ( try_alpha < 0.0 )
+        add_alpha = -1.0 * alpha[max_kkt_i];
+      else if (try_alpha > C)
+				add_alpha = C - alpha[max_kkt_i];
+      else
+        add_alpha = diff_alpha;
+
+      alpha[max_kkt_i] = alpha[max_kkt_i] + add_alpha;
+
+      if ( !is_computed[max_kkt_i] )
+      {
+        for ( i = 0; i < K; i++ )
+        {
+          A[i][max_kkt_i] = a[i].dot(a[max_kkt_i] ); // for version 1
+          //A[i][max_kkt_i] = 0; // for version 1
+          is_computed[max_kkt_i] = true;
+        }
+      }
+
+      for ( i = 0; i < F.size(); i++ )
+      {
+        F[i] -= add_alpha * A[i][max_kkt_i];
+        kkt[i] = F[i];
+        if (alpha[i] > C - zero)
+					kkt[i]=-kkt[i];
+				else if (alpha[i] > zero)
+					kkt[i] = abs(F[i]);
+
+      }
+      max_kkt = -1e100;
+      max_kkt_i = -1;
+      for ( i = 0; i < F.size(); i++ )
+        if ( kkt[i] > max_kkt )
+        {
+          max_kkt = kkt[i];
+          max_kkt_i = i;
+        }
+
+      iter++;
+    }
+
+    return alpha;
+  }
+}
diff --git a/dtrain/test/mtm11/mira_update/Hildreth.h b/dtrain/test/mtm11/mira_update/Hildreth.h
new file mode 100644
index 00000000..8d791085
--- /dev/null
+++ b/dtrain/test/mtm11/mira_update/Hildreth.h
@@ -0,0 +1,10 @@
+#include "sparse_vector.h"
+
+namespace Mira {
+  class Hildreth {
+  public :
+    static std::vector<double> optimise(std::vector< SparseVector<double> >& a, std::vector<double>& b);
+    static std::vector<double> optimise(std::vector< SparseVector<double> >& a, std::vector<double>& b, double C);
+  };
+}
+
diff --git a/dtrain/test/mtm11/mira_update/dtrain.cc b/dtrain/test/mtm11/mira_update/dtrain.cc
new file mode 100644
index 00000000..933417a4
--- /dev/null
+++ b/dtrain/test/mtm11/mira_update/dtrain.cc
@@ -0,0 +1,532 @@
+#include "common.h"
+#include "kbestget.h"
+#include "util.h"
+#include "sample.h"
+#include "Hildreth.h"
+
+#include "ksampler.h"
+
+// boost compression
+#include <boost/iostreams/device/file.hpp> 
+#include <boost/iostreams/filtering_stream.hpp>
+#include <boost/iostreams/filter/gzip.hpp>
+//#include <boost/iostreams/filter/zlib.hpp>
+//#include <boost/iostreams/filter/bzip2.hpp>
+using namespace boost::iostreams;
+
+
+#ifdef DTRAIN_DEBUG
+#include "tests.h"
+#endif
+
+
+/*
+ * init
+ *
+ */
+bool
+init(int argc, char** argv, po::variables_map* cfg)
+{
+  po::options_description conff( "Configuration File Options" );
+  size_t k, N, T, stop, n_pairs;
+  string s, f, update_type;
+  conff.add_options()
+    ( "decoder_config", po::value<string>(),                            "configuration file for cdec" )
+    ( "kbest",          po::value<size_t>(&k)->default_value(DTRAIN_DEFAULT_K),         "k for kbest" )
+    ( "ngrams",         po::value<size_t>(&N)->default_value(DTRAIN_DEFAULT_N),        "N for Ngrams" )
+    ( "filter",         po::value<string>(&f)->default_value("unique"),           "filter kbest list" )
+    ( "epochs",         po::value<size_t>(&T)->default_value(DTRAIN_DEFAULT_T),   "# of iterations T" ) 
+    ( "input",          po::value<string>(),                                             "input file" )
+    ( "scorer",         po::value<string>(&s)->default_value(DTRAIN_DEFAULT_SCORER), "scoring metric" )
+    ( "output",         po::value<string>(),                                    "output weights file" )
+    ( "stop_after",     po::value<size_t>(&stop)->default_value(0),    "stop after X input sentences" )
+    ( "weights_file",   po::value<string>(),      "input weights file (e.g. from previous iteration)" )
+    ( "wprint",         po::value<string>(),                     "weights to print on each iteration" )
+    ( "noup",           po::value<bool>()->zero_tokens(),                     "do not update weights" );
+
+  po::options_description clo("Command Line Options");
+  clo.add_options()
+    ( "config,c",         po::value<string>(),              "dtrain config file" )
+    ( "quiet,q",          po::value<bool>()->zero_tokens(),           "be quiet" )
+    ( "update-type",      po::value<string>(&update_type)->default_value("mira"), "perceptron or mira" )
+    ( "n-pairs",          po::value<size_t>(&n_pairs)->default_value(10), "number of pairs used to compute update" )
+    ( "verbose,v",        po::value<bool>()->zero_tokens(),         "be verbose" )
+#ifndef DTRAIN_DEBUG
+    ;
+#else
+    ( "test", "run tests and exit");
+#endif
+  po::options_description config_options, cmdline_options;
+
+  config_options.add(conff);
+  cmdline_options.add(clo);
+  cmdline_options.add(conff);
+
+  po::store( parse_command_line(argc, argv, cmdline_options), *cfg );
+  if ( cfg->count("config") ) {
+    ifstream config( (*cfg)["config"].as<string>().c_str() );
+    po::store( po::parse_config_file(config, config_options), *cfg );
+  }
+  po::notify(*cfg);
+
+  if ( !cfg->count("decoder_config") || !cfg->count("input") ) { 
+    cerr << cmdline_options << endl;
+    return false;
+  }
+  if ( cfg->count("noup") && cfg->count("decode") ) {
+    cerr << "You can't use 'noup' and 'decode' at once." << endl;
+    return false;
+  }
+  if ( cfg->count("filter") && (*cfg)["filter"].as<string>() != "unique"
+       && (*cfg)["filter"].as<string>() != "no" ) {
+    cerr << "Wrong 'filter' type: '" << (*cfg)["filter"].as<string>() << "'." << endl;
+  }
+  #ifdef DTRAIN_DEBUG       
+  if ( !cfg->count("test") ) {
+    cerr << cmdline_options << endl;
+    return false;
+  }
+  #endif
+  return true;
+}
+
+
+// output formatting
+ostream& _nopos( ostream& out ) { return out << resetiosflags( ios::showpos ); }
+ostream& _pos( ostream& out ) { return out << setiosflags( ios::showpos ); }
+ostream& _prec2( ostream& out ) { return out << setprecision(2); }
+ostream& _prec5( ostream& out ) { return out << setprecision(5); }
+
+
+
+
+/*
+ * dtrain
+ *
+ */
+int
+main( int argc, char** argv )
+{
+  cout << setprecision( 5 );
+  // handle most parameters
+  po::variables_map cfg;
+  if ( ! init(argc, argv, &cfg) ) exit(1); // something is wrong 
+#ifdef DTRAIN_DEBUG
+  if ( cfg.count("test") ) run_tests(); // run tests and exit 
+#endif
+  bool quiet = false;
+  if ( cfg.count("quiet") ) quiet = true;
+  bool verbose = false;  
+  if ( cfg.count("verbose") ) verbose = true;
+  bool noup = false;
+  if ( cfg.count("noup") ) noup = true;
+  const size_t k = cfg["kbest"].as<size_t>();
+  const size_t N = cfg["ngrams"].as<size_t>(); 
+  const size_t T = cfg["epochs"].as<size_t>();
+  const size_t stop_after = cfg["stop_after"].as<size_t>();
+  const string filter_type = cfg["filter"].as<string>();
+  const string update_type = cfg["update-type"].as<string>();
+  const size_t n_pairs = cfg["n-pairs"].as<size_t>();
+  const string output_file = cfg["output"].as<string>();
+  if ( !quiet ) {
+    cout << endl << "dtrain" << endl << "Parameters:" << endl;
+    cout << setw(25) << "k " << k << endl;
+    cout << setw(25) << "N " << N << endl;
+    cout << setw(25) << "T " << T << endl;
+    if ( cfg.count("stop-after") )
+      cout << setw(25) << "stop_after " << stop_after << endl;
+    if ( cfg.count("weights") )
+      cout << setw(25) << "weights " << cfg["weights"].as<string>() << endl;
+    cout << setw(25) << "input " << "'" << cfg["input"].as<string>() << "'" << endl;
+    cout << setw(25) << "filter " << "'" << filter_type << "'" << endl;
+  }
+
+  vector<string> wprint;
+  if ( cfg.count("wprint") ) {
+    boost::split( wprint, cfg["wprint"].as<string>(), boost::is_any_of(" ") );
+  }
+
+  // setup decoder, observer
+  register_feature_functions();
+  SetSilent(true);
+  ReadFile ini_rf( cfg["decoder_config"].as<string>() );
+  if ( !quiet )
+    cout << setw(25) << "cdec cfg " << "'" << cfg["decoder_config"].as<string>() << "'" << endl;
+  Decoder decoder( ini_rf.stream() );
+  //KBestGetter observer( k, filter_type );
+  MT19937 rng;
+  KSampler observer( k, &rng );
+
+  // scoring metric/scorer
+  string scorer_str = cfg["scorer"].as<string>();
+  double (*scorer)( NgramCounts&, const size_t, const size_t, size_t, vector<float> );
+  if ( scorer_str == "bleu" ) {
+    scorer = &bleu;
+  } else if ( scorer_str == "stupid_bleu" ) {
+    scorer = &stupid_bleu;
+  } else if ( scorer_str == "smooth_bleu" ) {
+    scorer = &smooth_bleu;
+  } else if ( scorer_str == "approx_bleu" ) {
+    scorer = &approx_bleu;
+  } else {
+    cerr << "Don't know scoring metric: '" << scorer_str << "', exiting." << endl;
+    exit(1);
+  }
+  // for approx_bleu
+  NgramCounts global_counts( N ); // counts for 1 best translations
+  size_t global_hyp_len = 0;      // sum hypothesis lengths
+  size_t global_ref_len = 0;      // sum reference lengths
+  // this is all BLEU implmentations
+  vector<float> bleu_weights; // we leave this empty -> 1/N; TODO? 
+  if ( !quiet ) cout << setw(26) << "scorer '" << scorer_str << "'" << endl << endl;
+
+  // init weights
+  Weights weights;
+  if ( cfg.count("weights") ) weights.InitFromFile( cfg["weights"].as<string>() );
+  SparseVector<double> lambdas;
+  weights.InitSparseVector( &lambdas );
+  vector<double> dense_weights;
+
+  // input
+  if ( !quiet && !verbose )
+    cout << "(a dot represents " << DTRAIN_DOTS << " lines of input)" << endl;
+  string input_fn = cfg["input"].as<string>();
+  ifstream input;
+  if ( input_fn != "-" ) input.open( input_fn.c_str() );
+  string in;
+  vector<string> in_split; // input: src\tref\tpsg
+  vector<string> ref_tok;  // tokenized reference
+  vector<WordID> ref_ids;  // reference as vector of WordID
+  string grammar_str;
+
+  // buffer input for t > 0
+  vector<string> src_str_buf;           // source strings, TODO? memory
+  vector<vector<WordID> > ref_ids_buf;  // references as WordID vecs
+  filtering_ostream grammar_buf;        // written to compressed file in /tmp
+  // this is for writing the grammar buffer file
+  grammar_buf.push( gzip_compressor() );
+  char grammar_buf_tmp_fn[] = DTRAIN_TMP_DIR"/dtrain-grammars-XXXXXX";
+  mkstemp( grammar_buf_tmp_fn );
+  grammar_buf.push( file_sink(grammar_buf_tmp_fn, ios::binary | ios::trunc) );
+  
+  size_t sid = 0, in_sz = 99999999; // sentence id, input size
+  double acc_1best_score = 0., acc_1best_model = 0.;
+  vector<vector<double> > scores_per_iter;
+  double max_score = 0.;
+  size_t best_t = 0;
+  bool next = false, stop = false;
+  double score = 0.;
+  size_t cand_len = 0;
+  double overall_time = 0.;
+
+  // for the perceptron/SVM; TODO as params
+  double eta = 0.0005;
+  double gamma = 0.;//01; // -> SVM
+  lambdas.add_value( FD::Convert("__bias"), 0 );
+  
+  // for random sampling
+  srand ( time(NULL) );
+
+
+  for ( size_t t = 0; t < T; t++ ) // T epochs
+  {
+
+  time_t start, end;  
+  time( &start );
+
+  // actually, we need only need this if t > 0 FIXME
+  ifstream grammar_file( grammar_buf_tmp_fn, ios_base::in | ios_base::binary );
+  filtering_istream grammar_buf_in;
+  grammar_buf_in.push( gzip_decompressor() );
+  grammar_buf_in.push( grammar_file );
+
+  // reset average scores
+  acc_1best_score = acc_1best_model = 0.;
+  
+  // reset sentence counter
+  sid = 0;
+  
+  if ( !quiet ) cout << "Iteration #" << t+1 << " of " << T << "." << endl;
+  
+  while( true )
+  {
+
+    // get input from stdin or file
+    in.clear();
+    next = stop = false; // next iteration, premature stop
+    if ( t == 0 ) {    
+      if ( input_fn == "-" ) {
+        if ( !getline(cin, in) ) next = true;
+      } else {
+        if ( !getline(input, in) ) next = true; 
+      }
+    } else {
+      if ( sid == in_sz ) next = true; // stop if we reach the end of our input
+    }
+    // stop after X sentences (but still iterate for those)
+    if ( stop_after > 0 && stop_after == sid && !next ) stop = true;
+    
+    // produce some pretty output
+    if ( !quiet && !verbose ) {
+        if ( sid == 0 ) cout << " ";
+        if ( (sid+1) % (DTRAIN_DOTS) == 0 ) {
+            cout << ".";
+            cout.flush();
+        }
+        if ( (sid+1) % (20*DTRAIN_DOTS) == 0) {
+            cout << " " << sid+1 << endl;
+            if ( !next && !stop ) cout << " ";
+        }
+        if ( stop ) {
+          if ( sid % (20*DTRAIN_DOTS) != 0 ) cout << " " << sid << endl;
+          cout << "Stopping after " << stop_after << " input sentences." << endl;
+        } else {
+          if ( next ) {
+            if ( sid % (20*DTRAIN_DOTS) != 0 ) {
+              cout << " " << sid << endl;
+            }
+          }
+        }
+    }
+    
+    // next iteration
+    if ( next || stop ) break;
+
+    // weights
+    dense_weights.clear();
+    weights.InitFromVector( lambdas );
+    weights.InitVector( &dense_weights );
+    decoder.SetWeights( dense_weights );
+
+    if ( t == 0 ) {
+      // handling input
+      in_split.clear();
+      boost::split( in_split, in, boost::is_any_of("\t") ); // in_split[0] is id
+      // getting reference
+      ref_tok.clear(); ref_ids.clear();
+      boost::split( ref_tok, in_split[2], boost::is_any_of(" ") );
+      register_and_convert( ref_tok, ref_ids );
+      ref_ids_buf.push_back( ref_ids );
+      // process and set grammar
+      bool broken_grammar = true;
+      for ( string::iterator ti = in_split[3].begin(); ti != in_split[3].end(); ti++ ) {
+        if ( !isspace(*ti) ) {
+          broken_grammar = false;
+          break;
+        }
+      }
+      if ( broken_grammar ) continue;
+      grammar_str = boost::replace_all_copy( in_split[3], " __NEXT__RULE__ ", "\n" ) + "\n"; // FIXME copy, __
+      grammar_buf << grammar_str << DTRAIN_GRAMMAR_DELIM << endl;
+      decoder.SetSentenceGrammarFromString( grammar_str );
+      // decode, kbest
+      src_str_buf.push_back( in_split[1] );
+      decoder.Decode( in_split[1], &observer );
+    } else {
+      // get buffered grammar
+      grammar_str.clear();
+      int i = 1;
+      while ( true ) {
+        string g;  
+        getline( grammar_buf_in, g );
+        if ( g == DTRAIN_GRAMMAR_DELIM ) break;
+        grammar_str += g+"\n";
+        i += 1;
+      }
+      decoder.SetSentenceGrammarFromString( grammar_str );
+      // decode, kbest
+      decoder.Decode( src_str_buf[sid], &observer );
+    }
+
+    // get kbest list
+    KBestList* kb;
+    //if ( ) { // TODO get from forest
+      kb = observer.GetKBest();
+    //}
+
+    // scoring kbest
+    if ( t > 0 ) ref_ids = ref_ids_buf[sid];
+    for ( size_t i = 0; i < kb->GetSize(); i++ ) {
+      NgramCounts counts = make_ngram_counts( ref_ids, kb->sents[i], N );
+      // this is for approx bleu
+      if ( scorer_str == "approx_bleu" ) {
+        if ( i == 0 ) { // 'context of 1best translations'
+          global_counts  += counts;
+          global_hyp_len += kb->sents[i].size();
+          global_ref_len += ref_ids.size();
+          counts.reset();
+          cand_len = 0;
+        } else {
+            cand_len = kb->sents[i].size();
+        }
+        NgramCounts counts_tmp = global_counts + counts;
+        // TODO as param
+        score = 0.9 * scorer( counts_tmp,
+                              global_ref_len,
+                              global_hyp_len + cand_len, N, bleu_weights );
+      } else {
+        // other scorers
+        cand_len = kb->sents[i].size();
+        score = scorer( counts,
+                        ref_ids.size(),
+                        kb->sents[i].size(), N, bleu_weights );
+      }
+
+      kb->scores.push_back( score );
+
+      if ( i == 0 ) {
+        acc_1best_score += score;
+        acc_1best_model += kb->model_scores[i];
+      }
+
+      if ( verbose ) {
+        if ( i == 0 ) cout << "'" << TD::GetString( ref_ids ) << "' [ref]" << endl;
+        cout << _prec5 << _nopos << "[hyp " << i << "] " << "'" << TD::GetString( kb->sents[i] ) << "'";
+        cout << " [SCORE=" << score << ",model="<< kb->model_scores[i] << "]" << endl;
+        cout << kb->feats[i] << endl; // this is maybe too verbose
+      }
+    } // Nbest loop
+
+    if ( verbose ) cout << endl;
+
+
+    // UPDATE WEIGHTS
+    if ( !noup ) {
+
+      TrainingInstances pairs;
+      sample_all( kb, pairs, n_pairs );
+       
+      vector< SparseVector<double> > featureValueDiffs;
+      vector<double> lossMinusModelScoreDiffs;
+      for ( TrainingInstances::iterator ti = pairs.begin();
+            ti != pairs.end(); ti++ ) {
+
+        SparseVector<double> dv;
+        if ( ti->first_score - ti->second_score < 0 ) {
+          dv = ti->second - ti->first;
+          dv.add_value( FD::Convert("__bias"), -1 );
+        
+	  featureValueDiffs.push_back(dv);
+	  double lossMinusModelScoreDiff = ti->loss_diff - ti->model_score_diff;
+	  lossMinusModelScoreDiffs.push_back(lossMinusModelScoreDiff);
+
+	  if (update_type == "perceptron") {
+	    lambdas += dv * eta;
+	    cerr << "after perceptron update: " << lambdas << endl << endl;
+	  }
+
+          if ( verbose ) {
+            cout << "{{ f("<< ti->first_rank <<") > f(" << ti->second_rank << ") but g(i)="<< ti->first_score <<" < g(j)="<< ti->second_score << " so update" << endl;
+            cout << " i  " << TD::GetString(kb->sents[ti->first_rank]) << endl;
+            cout << "    " << kb->feats[ti->first_rank] << endl;
+            cout << " j  " << TD::GetString(kb->sents[ti->second_rank]) << endl;
+            cout << "    " << kb->feats[ti->second_rank] << endl; 
+            cout << " diff vec: " << dv << endl;
+            cout << " lambdas after update: " << lambdas << endl;
+            cout << "}}" << endl;
+          }
+        } else {
+          //SparseVector<double> reg;
+          //reg = lambdas * ( 2 * gamma );
+          //lambdas += reg * ( -eta );
+        }
+      }
+      cerr << "Collected " << featureValueDiffs.size() << " constraints." << endl;
+
+      double slack = 0.01;
+      if (update_type == "mira") {
+	if (featureValueDiffs.size() > 0) {
+	  vector<double> alphas;
+	  if (slack != 0) {
+	    alphas = Mira::Hildreth::optimise(featureValueDiffs, lossMinusModelScoreDiffs, slack);
+	  } else {
+	    alphas = Mira::Hildreth::optimise(featureValueDiffs, lossMinusModelScoreDiffs);
+	  }
+	  
+	  for (size_t k = 0; k < featureValueDiffs.size(); ++k) {
+	    lambdas += featureValueDiffs[k] * alphas[k];
+	  }
+	  //	  cerr << "after mira update: " << lambdas << endl << endl;
+	}      
+      }
+    }
+
+    ++sid;
+
+  } // input loop
+
+  if ( t == 0 ) in_sz = sid; // remember size (lines) of input
+
+  // print some stats
+  double avg_1best_score = acc_1best_score/(double)in_sz;
+  double avg_1best_model = acc_1best_model/(double)in_sz;
+  double avg_1best_score_diff, avg_1best_model_diff;
+  if ( t > 0 ) {
+    avg_1best_score_diff = avg_1best_score - scores_per_iter[t-1][0];
+    avg_1best_model_diff = avg_1best_model - scores_per_iter[t-1][1];
+  } else {
+    avg_1best_score_diff = avg_1best_score;
+    avg_1best_model_diff = avg_1best_model;
+  }
+  cout << _prec5 << _pos << "WEIGHTS" << endl;
+  for (vector<string>::iterator it = wprint.begin(); it != wprint.end(); it++) {
+    cout << setw(16) << *it << " = " << dense_weights[FD::Convert( *it )] << endl;
+  }
+
+  cout << "        ---" << endl;
+  cout << _nopos << "      avg score: " << avg_1best_score;
+  cout << _pos << " (" << avg_1best_score_diff << ")" << endl;
+  cout << _nopos << "avg model score: " << avg_1best_model;
+  cout << _pos << " (" << avg_1best_model_diff << ")" << endl;
+  vector<double> remember_scores;
+  remember_scores.push_back( avg_1best_score );
+  remember_scores.push_back( avg_1best_model );
+  scores_per_iter.push_back( remember_scores );
+  if ( avg_1best_score > max_score ) {
+    max_score = avg_1best_score;
+    best_t = t;
+  }
+
+  // close open files
+  if ( input_fn != "-" ) input.close();
+  close( grammar_buf );
+  grammar_file.close();
+
+  time ( &end );
+  double time_dif = difftime( end, start );
+  overall_time += time_dif;
+  if ( !quiet ) {
+    cout << _prec2 << _nopos << "(time " << time_dif/60. << " min, ";
+    cout << time_dif/(double)in_sz<< " s/S)" << endl;
+  }
+  
+  if ( t+1 != T ) cout << endl;
+
+  if ( noup ) break;
+
+  // write weights after every epoch                                                                                                                                               
+  std::string s;
+  std::stringstream out;
+  out << t;
+  s = out.str();
+  string weights_file = output_file + "." + s;
+  weights.WriteToFile(weights_file, true );
+
+  } // outer loop
+
+  unlink( grammar_buf_tmp_fn );
+  if ( !noup ) {
+    if ( !quiet ) cout << endl << "writing weights file '" << cfg["output"].as<string>() << "' ...";
+    weights.WriteToFile( cfg["output"].as<string>(), true );
+    if ( !quiet ) cout << "done" << endl;
+  }
+  
+  if ( !quiet ) {
+    cout << _prec5 << _nopos << endl << "---" << endl << "Best iteration: ";
+    cout << best_t+1 << " [SCORE '" << scorer_str << "'=" << max_score << "]." << endl;
+    cout << _prec2 << "This took " << overall_time/60. << " min." << endl;
+  }
+
+  return 0;
+}
+
diff --git a/dtrain/test/mtm11/mira_update/sample.h b/dtrain/test/mtm11/mira_update/sample.h
new file mode 100644
index 00000000..5c331bba
--- /dev/null
+++ b/dtrain/test/mtm11/mira_update/sample.h
@@ -0,0 +1,101 @@
+#ifndef _DTRAIN_SAMPLE_H_
+#define _DTRAIN_SAMPLE_H_
+
+
+#include "kbestget.h"
+
+
+namespace dtrain
+{
+
+
+struct TPair
+{
+  SparseVector<double> first, second;
+  size_t first_rank, second_rank;
+  double first_score, second_score;
+  double model_score_diff;
+  double loss_diff;
+};
+
+typedef vector<TPair> TrainingInstances;
+
+
+void
+  sample_all( KBestList* kb, TrainingInstances &training, size_t n_pairs )
+{
+  std::vector<double> loss_diffs;
+  TrainingInstances training_tmp;
+  for ( size_t i = 0; i < kb->GetSize()-1; i++ ) {
+    for ( size_t j = i+1; j < kb->GetSize(); j++ ) {
+      TPair p;
+      p.first = kb->feats[i];
+      p.second = kb->feats[j];
+      p.first_rank = i;
+      p.second_rank = j;
+      p.first_score = kb->scores[i];
+      p.second_score = kb->scores[j];
+
+      bool conservative = 1;
+      if ( kb->scores[i] - kb->scores[j] < 0 ) {
+	// j=hope, i=fear                                                                                                                         
+	p.model_score_diff = kb->model_scores[j] - kb->model_scores[i];
+        p.loss_diff = kb->scores[j] - kb->scores[i];
+        training_tmp.push_back(p);
+        loss_diffs.push_back(p.loss_diff);
+      }
+      else if (!conservative) {
+	// i=hope, j=fear
+	p.model_score_diff = kb->model_scores[i] - kb->model_scores[j];
+        p.loss_diff = kb->scores[i] - kb->scores[j];
+        training_tmp.push_back(p);
+        loss_diffs.push_back(p.loss_diff);
+      }
+    }
+  }
+  
+  if (training_tmp.size() > 0) {
+    double threshold;
+    std::sort(loss_diffs.begin(), loss_diffs.end());
+    std::reverse(loss_diffs.begin(), loss_diffs.end());
+    threshold = loss_diffs.size() >= n_pairs ? loss_diffs[n_pairs-1] : loss_diffs[loss_diffs.size()-1];
+    cerr << "threshold: " << threshold << endl;
+    size_t constraints = 0;
+    for (size_t i = 0; (i < training_tmp.size() && constraints < n_pairs); ++i) {
+      if (training_tmp[i].loss_diff >= threshold) {
+	training.push_back(training_tmp[i]);
+	constraints++;
+      }
+    }
+  }
+  else {
+    cerr << "No pairs selected." << endl;
+  }
+}
+
+void
+sample_rand( KBestList* kb, TrainingInstances &training )
+{
+  srand( time(NULL) );
+  for ( size_t i = 0; i < kb->GetSize()-1; i++ ) {
+    for ( size_t j = i+1; j < kb->GetSize(); j++ ) {
+      if ( rand() % 2 ) {
+        TPair p;
+        p.first = kb->feats[i];
+        p.second = kb->feats[j];
+        p.first_rank = i;
+        p.second_rank = j;
+        p.first_score = kb->scores[i];
+        p.second_score = kb->scores[j];
+        training.push_back( p );
+      }
+    }
+  }
+}
+
+
+} // namespace
+
+
+#endif
+