--- /dev/null
+
+///////////////////////////////////////////////////////////////////////////
+// This program is free software: you can redistribute it and/or modify //
+// it under the terms of the version 3 of the GNU General Public License //
+// as published by the Free Software Foundation. //
+// //
+// This program 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 //
+// General Public License for more details. //
+// //
+// You should have received a copy of the GNU General Public License //
+// along with this program. If not, see <http://www.gnu.org/licenses/>. //
+// //
+// Written by Francois Fleuret, (C) IDIAP //
+// Contact <francois.fleuret@idiap.ch> for comments & bug reports //
+///////////////////////////////////////////////////////////////////////////
+
+#include "classifier_reader.h"
+#include "fusion_sort.h"
+
+#include "boosted_classifier.h"
+#include "tools.h"
+
+BoostedClassifier::BoostedClassifier(int nb_weak_learners) {
+ _loss_type = global.loss_type;
+ _nb_weak_learners = nb_weak_learners;
+ _weak_learners = 0;
+}
+
+BoostedClassifier::BoostedClassifier() {
+ _loss_type = global.loss_type;
+ _nb_weak_learners = 0;
+ _weak_learners = 0;
+}
+
+BoostedClassifier::~BoostedClassifier() {
+ if(_weak_learners) {
+ for(int w = 0; w < _nb_weak_learners; w++)
+ delete _weak_learners[w];
+ delete[] _weak_learners;
+ }
+}
+
+scalar_t BoostedClassifier::response(SampleSet *sample_set, int n_sample) {
+ scalar_t r = 0;
+ for(int w = 0; w < _nb_weak_learners; w++) {
+ r += _weak_learners[w]->response(sample_set, n_sample);
+ ASSERT(!isnan(r));
+ }
+ return r;
+}
+
+void BoostedClassifier::train(LossMachine *loss_machine,
+ SampleSet *sample_set, scalar_t *train_responses) {
+
+ if(_weak_learners) {
+ cerr << "Can not re-train a BoostedClassifier" << endl;
+ exit(1);
+ }
+
+ int nb_pos = 0, nb_neg = 0;
+
+ for(int s = 0; s < sample_set->nb_samples(); s++) {
+ if(sample_set->label(s) > 0) nb_pos++;
+ else if(sample_set->label(s) < 0) nb_neg++;
+ }
+
+ _weak_learners = new DecisionTree *[_nb_weak_learners];
+
+ (*global.log_stream) << "With " << nb_pos << " positive and " << nb_neg << " negative samples." << endl;
+
+ for(int w = 0; w < _nb_weak_learners; w++) {
+
+ _weak_learners[w] = new DecisionTree();
+ _weak_learners[w]->train(loss_machine, sample_set, train_responses);
+
+ for(int n = 0; n < sample_set->nb_samples(); n++)
+ train_responses[n] += _weak_learners[w]->response(sample_set, n);
+
+ (*global.log_stream) << "Weak learner " << w
+ << " depth " << _weak_learners[w]->depth()
+ << " nb_leaves " << _weak_learners[w]->nb_leaves()
+ << " train loss " << loss_machine->loss(sample_set, train_responses)
+ << endl;
+
+ }
+
+ (*global.log_stream) << "Built a classifier with " << _nb_weak_learners << " weak_learners." << endl;
+}
+
+void BoostedClassifier::tag_used_features(bool *used) {
+ for(int w = 0; w < _nb_weak_learners; w++)
+ _weak_learners[w]->tag_used_features(used);
+}
+
+void BoostedClassifier::re_index_features(int *new_indexes) {
+ for(int w = 0; w < _nb_weak_learners; w++)
+ _weak_learners[w]->re_index_features(new_indexes);
+}
+
+void BoostedClassifier::read(istream *is) {
+ if(_weak_learners) {
+ cerr << "Can not read over an existing BoostedClassifier" << endl;
+ exit(1);
+ }
+
+ read_var(is, &_nb_weak_learners);
+ _weak_learners = new DecisionTree *[_nb_weak_learners];
+ for(int w = 0; w < _nb_weak_learners; w++) {
+ _weak_learners[w] = new DecisionTree();
+ _weak_learners[w]->read(is);
+ (*global.log_stream) << "Read tree " << w << " of depth "
+ << _weak_learners[w]->depth() << " with "
+ << _weak_learners[w]->nb_leaves() << " leaves." << endl;
+ }
+
+ (*global.log_stream)
+ << "Read BoostedClassifier containing " << _nb_weak_learners << " weak learners." << endl;
+}
+
+void BoostedClassifier::write(ostream *os) {
+ unsigned int id;
+ id = CLASSIFIER_BOOSTED;
+ write_var(os, &id);
+
+ write_var(os, &_nb_weak_learners);
+ for(int w = 0; w < _nb_weak_learners; w++)
+ _weak_learners[w]->write(os);
+}