void bilou_ner_trainer::train(ner_id id, int stages, const network_parameters& parameters, const tagger& tagger,
istream& features, istream& train, istream& heldout, ostream& os) {
if (stages <= 0) runtime_failure("Cannot train NER with <= 0 stages!");
if (stages >= 256) runtime_failure("Cannot train NER with >= 256 stages!");
// Load training and possibly also heldout data
entity_map entities;
vector<labelled_sentence> train_data;
cerr << "Loading train data: ";
load_data(train, tagger, train_data, entities, true);
cerr << "done, " << train_data.size() << " sentences" << endl;
cerr << "Found " << entities.size() << " annotated entity types." << endl;
vector<labelled_sentence> heldout_data;
if (heldout) {
cerr << "Loading heldout data: ";
load_data(heldout, tagger, heldout_data, entities, false);
cerr << "done, " << heldout_data.size() << " sentences" << endl;
}
// Parse feature templates
feature_templates templates;
unique_ptr<tokenizer> tokenizer(bilou_ner::new_tokenizer(id));
cerr << "Parsing feature templates: ";
templates.parse(features, entities, nlp_pipeline(tokenizer.get(), &tagger));
cerr << "done" << endl;
// Train required number of stages
vector<network_classifier> networks(stages);
for (auto&& network : networks) {
// Generate features
cerr << "Generating features: ";
vector<classifier_instance> train_instances, heldout_instances;
generate_instances(train_data, templates, train_instances, true);
generate_instances(heldout_data, templates, heldout_instances, false);
cerr << "done" << endl;
// Train and encode the recognizer
cerr << "Training network classifier." << endl;
if (!network.train(templates.get_total_features(), bilou_entity::total(entities.size()), train_instances, heldout_instances, parameters, true))
runtime_failure("Cannot train the network classifier!");
// Use the trained classifier to compute previous_stage
compute_previous_stage(train_data, templates, network);
compute_previous_stage(heldout_data, templates, network);
}
// Encode the recognizer
cerr << "Encoding the recognizer." << endl;
if (!entities.save(os)) runtime_error("Cannot save entity map!");
if (!templates.save(os)) runtime_error("Cannot save feature templates!");
if (!os.put(stages)) runtime_error("Cannot save number of stages!");
for (auto&& network : networks)
if (!network.save(os)) runtime_error("Cannot save classifier network!");
}
void bilou_ner_trainer::load_data(istream& is, const tagger& tagger, vector<labelled_sentence>& data, entity_map& entity_map, bool add_entities) {
vector<string> words, entities;
vector<string_piece> forms;
data.clear();
string line;
vector<string> tokens;
for (bool eof; true; ) {
eof = !getline(is, line);
if (eof || line.empty()) {
if (!words.empty()) {
// Tag the sentence
forms.clear();
for (auto&& word : words)
forms.emplace_back(word);
data.emplace_back();
auto& sentence = data.back();
tagger.tag(forms, sentence.sentence);
// Clear previous_stage
sentence.sentence.clear_previous_stage();
// Decode the entities names and ranges
for (unsigned i = 0; i < entities.size(); i++)
if (entities[i] == "_" || entities[i] == "O")
sentence.outcomes.emplace_back(bilou_entity::O);
else if (entities[i].size() >= 3 && (entities[i].compare(0, 2, "I-") == 0 || entities[i].compare(0, 2, "B-") == 0)) {
bool has_prev = i > 0 && entities[i][0] == 'I' && entities[i-1].compare(1, string::npos, entities[i], 1, string::npos) == 0;
bool has_next = i+1 < entities.size() && entities[i+1][0] != 'B' && entities[i+1].compare(1, string::npos, entities[i], 1, string::npos) == 0;
entity_type entity = entity_map.parse(entities[i].c_str() + 2, add_entities);
sentence.outcomes.emplace_back(!has_prev && !has_next ? bilou_entity::U(entity) : !has_prev && has_next ? bilou_entity::B(entity) : has_prev && has_next ? bilou_entity::I : bilou_entity::L);
}
else
runtime_failure("Cannot parse entity type " << entities[i] << "!");
// Start a new sentence
words.clear();
entities.clear();
}
if (eof) break;
} else {
split(line, '\t', tokens);
if (tokens.size() != 2) runtime_failure("The NER data line '" << line << "' does not contain two columns!");
words.emplace_back(tokens[0]);
entities.emplace_back(tokens[1]);
}
}
}
void feature_templates::parse(istream& is, entity_map& entities) {
sentence_processors.clear();
entity_processors.clear();
total_features = 1; // An omnipresent feature used in process_sentence
string line;
vector<string> tokens;
while (getline(is, line)) {
// Ignore empty lines and lines commented with #
if (line.empty() || line[0] == '#') continue;
split(line, ' ', tokens);
if (tokens.size() < 1) runtime_failure("Bad line '" << line << "' of feature templates file!");
vector<string> token0_parts;
split(tokens[0], '/', token0_parts);
if (token0_parts.size() < 1 || token0_parts.size() > 2) runtime_failure("Bad feature template description at line '" << line << "' of feature templates file!");
string template_name = token0_parts[0];
int window = token0_parts.size() > 1 ? parse_int(token0_parts[1].c_str(), "feature_template_window") : 0;
vector<string> args;
for (unsigned i = 1; i < tokens.size(); i++)
args.emplace_back(tokens[i]);
// Try sentence processor
auto* maybe_sentence_processor = sentence_processor::create(template_name);
if (maybe_sentence_processor) {
if (!maybe_sentence_processor->parse(window, args, entities, &total_features)) runtime_failure("Cannot initialize feature template sentence processor '" << template_name << "' from line '" << line << "' of feature templates file!");
sentence_processors.emplace_back(template_name, maybe_sentence_processor);
continue;
}
// Try entity processor
auto* maybe_entity_processor = entity_processor::create(template_name);
if (maybe_entity_processor) {
if (window) cerr << "Ignoring window of " << window << " specified in entity_processor '" << template_name << "'." << endl;
if (!maybe_entity_processor->parse(args, entities)) runtime_failure("Cannot initialize feature template entity processor '" << template_name << "' from line '" << line << "' of feature templates file!");
entity_processors.emplace_back(template_name, maybe_entity_processor);
continue;
}
// Fail
runtime_failure("Cannot create feature template '" << template_name << "' from line '" << line << "' of feature templates file!");
}
}
void derivator_dictionary_encoder::encode(istream& is, istream& dictionary, bool verbose, ostream& os) {
// Load the morphology
cerr << "Loading morphology: ";
auto dictionary_start = dictionary.tellg();
unique_ptr<morpho> morpho(morpho::load(dictionary));
if (!morpho) runtime_failure("Cannot load morpho model from given file!");
if (morpho->get_derivator()) runtime_failure("The given morpho model already has a derivator!");
auto dictionary_end = dictionary.tellg();
cerr << "done" << endl;
// Load the derivator
cerr << "Loading derivator data: ";
struct lemma_info {
string sense;
string comment;
string parent;
set<string> parents;
unsigned children;
unsigned mark;
lemma_info(const string& sense = string(), const string& comment = string())
: sense(sense), comment(comment), children(0), mark(0) {}
};
map<string, lemma_info> derinet;
string line;
string part_lid, lemma_lid, lemma_comment;
vector<string> tokens;
vector<string> parts;
unordered_map<string, lemma_info> matched[2];
vector<tagged_lemma_forms> matched_lemmas_forms;
while (getline(is, line)) {
split(line, '\t', tokens);
if (tokens.size() != 2) runtime_failure("Expected two tab separated columns on derivator line '" << line << "'!");
// Generate all possible lemmas and parents
for (int i = 0; i < 2; i++) {
split(tokens[i], ' ', parts);
if (parts.size() > 2) runtime_failure("The derivator lemma desctiption '" << tokens[i] << "' contains two or more spaces!");
bool is_lemma_id = parts.size() == 1;
part_lid.assign(parts[0], 0, morpho->lemma_id_len(parts[0]));
morpho->generate(parts[0], is_lemma_id ? nullptr : parts[1].c_str(), morpho::NO_GUESSER, matched_lemmas_forms);
matched[i].clear();
for (auto&& lemma_forms : matched_lemmas_forms) {
lemma_lid.assign(lemma_forms.lemma, 0, morpho->lemma_id_len(lemma_forms.lemma));
if (!is_lemma_id || part_lid == lemma_lid) {
// Choose only the shortest lemma comment for the lemma id of lemma_form.lemma
lemma_comment.assign(lemma_forms.lemma, lemma_lid.size(), string::npos);
auto it = matched[i].emplace(lemma_lid, lemma_info(lemma_lid.substr(morpho->raw_lemma_len(lemma_lid)), lemma_comment));
if (!it.second &&
(lemma_comment.size() < it.first->second.comment.size() ||
(lemma_comment.size() == it.first->second.comment.size() && lemma_comment < it.first->second.comment)))
it.first->second.comment.assign(lemma_comment);
}
}
}
if (matched[0].empty() || matched[1].empty()) {
if (verbose)
cerr << "Could not match a lemma from line '" << line << "', skipping." << endl;
continue;
}
// Store the possible parents
derinet.insert(matched[0].begin(), matched[0].end());
derinet.insert(matched[1].begin(), matched[1].end());
for (auto&& lemma : matched[0])
for (auto&& parent : matched[1])
derinet[lemma.first].parents.insert(parent.first);
}
cerr << "done" << endl;
// Choose unique parent for every lemma
for (auto&& lemma : derinet)
if (!lemma.second.parents.empty()) {
// Try locating lexicographically smallest parent with the same sense
for (auto&& parent : lemma.second.parents)
if (derinet[parent].sense == lemma.second.sense) {
lemma.second.parent.assign(parent);
break;
}
// Otherwise, choose the lexicographically smallest parent
if (lemma.second.parent.empty())
lemma.second.parent.assign(*lemma.second.parents.begin());
// Add this edge also to the parent
derinet[lemma.second.parent].children++;
if (verbose)
cerr << lemma.first << lemma.second.comment << " -> " << lemma.second.parent << derinet[lemma.second.parent].comment << endl;
}
// Make sure the derinet contains no cycles
unsigned mark = 0;
for (auto&& lemma : derinet) {
lemma.second.mark = ++mark;
for (auto node = derinet.find(lemma.first); !node->second.parent.empty(); ) {
node = derinet.find(node->second.parent);
if (node->second.mark) {
if (node->second.mark == mark)
runtime_failure("The derivator data contains a cycle with lemma '" << lemma.first << "'!");
break;
}
node->second.mark = mark;
}
}
// Encode the derivator
cerr << "Encoding derivator: ";
os.put(morpho_ids::DERIVATOR_DICTIONARY);
binary_encoder enc;
vector<int> lengths;
for (auto&& lemma : derinet) {
if (lemma.first.size() >= lengths.size())
lengths.resize(lemma.first.size() + 1);
lengths[lemma.first.size()]++;
}
enc.add_1B(lengths.size());
for (auto&& length : lengths)
enc.add_4B(length);
enc.add_4B(derinet.size());
string prev = "";
for (auto&& lemma : derinet) {
int cpl = 0;
while (prev[cpl] && prev[cpl] == lemma.first[cpl]) cpl++;
enc.add_1B(prev.size() - cpl);
enc.add_1B(lemma.first.size() - cpl);
enc.add_data(lemma.first.c_str() + cpl);
enc.add_1B(lemma.second.comment.size());
enc.add_data(lemma.second.comment);
enc.add_2B(lemma.second.children);
if (lemma.second.parent.empty()) {
enc.add_1B(0);
} else {
unsigned best_lemma_from = 0, best_parent_from = 0, best_len = 0;
for (unsigned lemma_from = 0; lemma_from < lemma.first.size(); lemma_from++)
for (unsigned parent_from = 0; parent_from < lemma.second.parent.size(); parent_from++) {
unsigned len = 0;
while (lemma_from + len < lemma.first.size() &&
parent_from + len < lemma.second.parent.size() &&
lemma.first[lemma_from+len] == lemma.second.parent[parent_from+len])
len++;
if (len > best_len) best_lemma_from = lemma_from, best_parent_from = parent_from, best_len = len;
}
enum { REMOVE_START = 1, REMOVE_END = 2, ADD_START = 4, ADD_END = 8 };
enc.add_1B(REMOVE_START * (best_lemma_from>0) + REMOVE_END * (best_lemma_from+best_len<lemma.first.size()) +
ADD_START * (best_parent_from>0) + ADD_END * (best_parent_from+best_len<lemma.second.parent.size()));
if (best_lemma_from > 0) enc.add_1B(best_lemma_from);
if (best_lemma_from + best_len < lemma.first.size()) enc.add_1B(lemma.first.size() - best_lemma_from - best_len);
if (best_parent_from > 0) {
enc.add_1B(best_parent_from);
enc.add_data(string_piece(lemma.second.parent.c_str(), best_parent_from));
}
if (best_parent_from + best_len < lemma.second.parent.size()) {
enc.add_1B(lemma.second.parent.size() - best_parent_from - best_len);
enc.add_data(lemma.second.parent.c_str() + best_parent_from + best_len);
}
}
prev.assign(lemma.first);
}
compressor::save(os, enc);
// Append the morphology after the derivator dictionary model
if (!dictionary.seekg(dictionary_start, dictionary.beg)) runtime_failure("Cannot seek in the morpho model!");
for (auto length = dictionary_end - dictionary_start; length; length--)
os.put(dictionary.get());
cerr << "done" << endl;
}
