int32_t CShareBoost::choose_feature()
{
SGVector<float64_t> l1norm(m_fea.num_rows);
for (int32_t j=0; j < m_fea.num_rows; ++j)
{
if (std::find(&m_activeset[0], &m_activeset[m_activeset.vlen], j) !=
&m_activeset[m_activeset.vlen])
{
l1norm[j] = 0;
}
else
{
l1norm[j] = 0;
CMulticlassLabels *lab = dynamic_cast<CMulticlassLabels *>(m_labels);
for (int32_t k=0; k < m_multiclass_strategy->get_num_classes(); ++k)
{
float64_t abssum = 0;
for (int32_t ii=0; ii < m_fea.num_cols; ++ii)
{
abssum += m_fea(j, ii)*(m_rho(k, ii)/m_rho_norm[ii] -
(j == lab->get_int_label(ii)));
}
l1norm[j] += CMath::abs(abssum);
}
l1norm[j] /= m_fea.num_cols;
}
}
return SGVector<float64_t>::arg_max(l1norm.vector, 1, l1norm.vlen);
}
int main(int argc, char** argv)
{
init_shogun_with_defaults();
/* dense features from matrix */
CCSVFile* feature_file = new CCSVFile(fname_feats);
SGMatrix<float64_t> mat=SGMatrix<float64_t>();
mat.load(feature_file);
SG_UNREF(feature_file);
CDenseFeatures<float64_t>* features=new CDenseFeatures<float64_t>(mat);
SG_REF(features);
/* labels from vector */
CCSVFile* label_file = new CCSVFile(fname_labels);
SGVector<float64_t> label_vec;
label_vec.load(label_file);
SG_UNREF(label_file);
CMulticlassLabels* labels=new CMulticlassLabels(label_vec);
SG_REF(labels);
SG_SPRINT("Performing ShareBoost on a %d-class problem\n", labels->get_num_classes());
// Create ShareBoost Machine
CShareBoost *machine = new CShareBoost(features, labels, 10);
SG_REF(machine);
machine->train();
SGVector<int32_t> activeset = machine->get_activeset();
SG_SPRINT("%d out of %d features are selected:\n", activeset.vlen, mat.num_rows);
for (int32_t i=0; i < activeset.vlen; ++i)
SG_SPRINT("activeset[%02d] = %d\n", i, activeset[i]);
CDenseSubsetFeatures<float64_t> *subset_fea = new CDenseSubsetFeatures<float64_t>(features, machine->get_activeset());
SG_REF(subset_fea);
CMulticlassLabels* output = CLabelsFactory::to_multiclass(machine->apply(subset_fea));
int32_t correct = 0;
for (int32_t i=0; i < output->get_num_labels(); ++i)
if (output->get_int_label(i) == labels->get_int_label(i))
correct++;
SG_SPRINT("Accuracy = %.4f\n", float64_t(correct)/labels->get_num_labels());
// Free resources
SG_UNREF(machine);
SG_UNREF(output);
SG_UNREF(subset_fea);
SG_UNREF(features);
SG_UNREF(labels);
exit_shogun();
return 0;
}
void CShareBoost::compute_rho()
{
CMulticlassLabels *lab = dynamic_cast<CMulticlassLabels *>(m_labels);
for (int32_t i=0; i < m_rho.num_rows; ++i)
{ // i loop classes
for (int32_t j=0; j < m_rho.num_cols; ++j)
{ // j loop samples
int32_t label = lab->get_int_label(j);
m_rho(i,j) = CMath::exp((label == i) - m_pred(j, label) + m_pred(j, i));
}
}
// normalize
for (int32_t j=0; j < m_rho.num_cols; ++j)
{
m_rho_norm[j] = 0;
for (int32_t i=0; i < m_rho.num_rows; ++i)
m_rho_norm[j] += m_rho(i,j);
}
}
int main(int argc, char** argv)
{
int32_t num_vectors = 0;
int32_t num_feats = 0;
init_shogun_with_defaults();
const char*fname_train = "../data/7class_example4_train.dense";
CStreamingAsciiFile *train_file = new CStreamingAsciiFile(fname_train);
SG_REF(train_file);
CStreamingDenseFeatures<float64_t> *stream_features = new CStreamingDenseFeatures<float64_t>(train_file, true, 1024);
SG_REF(stream_features);
SGMatrix<float64_t> mat;
SGVector<float64_t> labvec(1000);
stream_features->start_parser();
SGVector< float64_t > vec;
while (stream_features->get_next_example())
{
vec = stream_features->get_vector();
if (num_feats == 0)
{
num_feats = vec.vlen;
mat = SGMatrix<float64_t>(num_feats, 1000);
}
std::copy(vec.vector, vec.vector+vec.vlen, mat.get_column_vector(num_vectors));
labvec[num_vectors] = stream_features->get_label();
num_vectors++;
stream_features->release_example();
}
stream_features->end_parser();
mat.num_cols = num_vectors;
labvec.vlen = num_vectors;
CMulticlassLabels* labels = new CMulticlassLabels(labvec);
SG_REF(labels);
// Create features with the useful values from mat
CDenseFeatures< float64_t >* features = new CDenseFeatures<float64_t>(mat);
SG_REF(features);
SG_SPRINT("Performing ShareBoost on a %d-class problem\n", labels->get_num_classes());
// Create ShareBoost Machine
CShareBoost *machine = new CShareBoost(features, labels, 10);
SG_REF(machine);
machine->train();
SGVector<int32_t> activeset = machine->get_activeset();
SG_SPRINT("%d out of %d features are selected:\n", activeset.vlen, mat.num_rows);
for (int32_t i=0; i < activeset.vlen; ++i)
SG_SPRINT("activeset[%02d] = %d\n", i, activeset[i]);
CDenseSubsetFeatures<float64_t> *subset_fea = new CDenseSubsetFeatures<float64_t>(features, machine->get_activeset());
SG_REF(subset_fea);
CMulticlassLabels* output = CMulticlassLabels::obtain_from_generic(machine->apply(subset_fea));
int32_t correct = 0;
for (int32_t i=0; i < output->get_num_labels(); ++i)
if (output->get_int_label(i) == labels->get_int_label(i))
correct++;
SG_SPRINT("Accuracy = %.4f\n", float64_t(correct)/labels->get_num_labels());
// Free resources
SG_UNREF(machine);
SG_UNREF(output);
SG_UNREF(subset_fea);
SG_UNREF(features);
SG_UNREF(labels);
SG_UNREF(train_file);
SG_UNREF(stream_features);
exit_shogun();
return 0;
}
SGVector<int32_t> CRelaxedTree::color_label_space(CSVM *svm, SGVector<int32_t> classes)
{
SGVector<int32_t> mu(classes.vlen);
CMulticlassLabels *labels = dynamic_cast<CMulticlassLabels *>(m_labels);
SGVector<float64_t> resp = eval_binary_model_K(svm);
ASSERT(resp.vlen == labels->get_num_labels())
SGVector<float64_t> xi_pos_class(classes.vlen), xi_neg_class(classes.vlen);
SGVector<float64_t> delta_pos(classes.vlen), delta_neg(classes.vlen);
for (int32_t i=0; i < classes.vlen; ++i)
{
// find number of instances from this class
int32_t ni=0;
for (int32_t j=0; j < labels->get_num_labels(); ++j)
{
if (labels->get_int_label(j) == classes[i])
{
ni++;
}
}
xi_pos_class[i] = 0;
xi_neg_class[i] = 0;
for (int32_t j=0; j < resp.vlen; ++j)
{
if (labels->get_int_label(j) == classes[i])
{
xi_pos_class[i] += std::max(0.0, 1 - resp[j]);
xi_neg_class[i] += std::max(0.0, 1 + resp[j]);
}
}
delta_pos[i] = 1.0/ni * xi_pos_class[i] - float64_t(m_A)/m_svm_C;
delta_neg[i] = 1.0/ni * xi_neg_class[i] - float64_t(m_A)/m_svm_C;
if (delta_pos[i] > 0 && delta_neg[i] > 0)
{
mu[i] = 0;
}
else
{
if (delta_pos[i] < delta_neg[i])
mu[i] = 1;
else
mu[i] = -1;
}
}
// enforce balance constraints
int32_t B_prime = 0;
for (int32_t i=0; i < mu.vlen; ++i)
B_prime += mu[i];
if (B_prime > m_B)
{
enforce_balance_constraints_upper(mu, delta_neg, delta_pos, B_prime, xi_neg_class);
}
if (B_prime < -m_B)
{
enforce_balance_constraints_lower(mu, delta_neg, delta_pos, B_prime, xi_neg_class);
}
int32_t npos = 0;
for (index_t i=0; i < mu.vlen; ++i)
{
if (mu[i] == 1)
npos++;
}
if (npos == 0)
{
// no positive class
index_t min_idx = SGVector<float64_t>::arg_min(xi_pos_class.vector, 1, xi_pos_class.vlen);
mu[min_idx] = 1;
}
int32_t nneg = 0;
for (index_t i=0; i < mu.vlen; ++i)
{
if (mu[i] == -1)
nneg++;
}
if (nneg == 0)
{
// no negative class
index_t min_idx = SGVector<float64_t>::arg_min(xi_neg_class.vector, 1, xi_neg_class.vlen);
if (mu[min_idx] == 1 && (npos == 0 || npos == 1))
{
// avoid overwritting the only positive class
float64_t min_val = 0;
int32_t i, min_i;
for (i=0; i < xi_neg_class.vlen; ++i)
{
if (mu[i] != 1)
{
min_val = xi_neg_class[i];
break;
}
}
min_i = i;
for (i=i+1; i < xi_neg_class.vlen; ++i)
{
if (mu[i] != 1 && xi_neg_class[i] < min_val)
{
min_val = xi_neg_class[i];
min_i = i;
}
}
mu[min_i] = -1;
}
else
{
mu[min_idx] = -1;
}
}
return mu;
}
SGVector<int32_t> CRelaxedTree::train_node_with_initialization(const CRelaxedTree::entry_t &mu_entry, SGVector<int32_t> classes, CSVM *svm)
{
SGVector<int32_t> mu(classes.vlen), prev_mu(classes.vlen);
mu.zero();
mu[mu_entry.first.first] = 1;
mu[mu_entry.first.second] = -1;
SGVector<int32_t> long_mu(m_num_classes);
svm->set_C(m_svm_C, m_svm_C);
svm->set_epsilon(m_svm_epsilon);
for (int32_t iiter=0; iiter < m_max_num_iter; ++iiter)
{
long_mu.zero();
for (int32_t i=0; i < classes.vlen; ++i)
{
if (mu[i] == 1)
long_mu[classes[i]] = 1;
else if (mu[i] == -1)
long_mu[classes[i]] = -1;
}
SGVector<int32_t> subset(m_feats->get_num_vectors());
SGVector<float64_t> binlab(m_feats->get_num_vectors());
int32_t k=0;
CMulticlassLabels *labs = dynamic_cast<CMulticlassLabels *>(m_labels);
for (int32_t i=0; i < binlab.vlen; ++i)
{
int32_t lab = labs->get_int_label(i);
binlab[i] = long_mu[lab];
if (long_mu[lab] != 0)
subset[k++] = i;
}
subset.vlen = k;
CBinaryLabels *binary_labels = new CBinaryLabels(binlab);
SG_REF(binary_labels);
binary_labels->add_subset(subset);
m_feats->add_subset(subset);
CKernel *kernel = (CKernel *)m_kernel->shallow_copy();
kernel->init(m_feats, m_feats);
svm->set_kernel(kernel);
svm->set_labels(binary_labels);
svm->train();
binary_labels->remove_subset();
m_feats->remove_subset();
SG_UNREF(binary_labels);
std::copy(&mu[0], &mu[mu.vlen], &prev_mu[0]);
mu = color_label_space(svm, classes);
bool bbreak = true;
for (int32_t i=0; i < mu.vlen; ++i)
{
if (mu[i] != prev_mu[i])
{
bbreak = false;
break;
}
}
if (bbreak)
break;
}
return mu;
}
int main()
{
init_shogun_with_defaults();
const char* train_file_name = "../data/7class_example4_train.dense";
const char* test_file_name = "../data/7class_example4_test.dense";
CStreamingAsciiFile* train_file = new CStreamingAsciiFile(train_file_name);
SG_REF(train_file);
CStreamingDenseFeatures<float32_t>* train_features = new CStreamingDenseFeatures<float32_t>(train_file, true, 1024);
SG_REF(train_features);
CRandomConditionalProbabilityTree *cpt = new CRandomConditionalProbabilityTree();
cpt->set_num_passes(1);
cpt->set_features(train_features);
cpt->train();
cpt->print_tree();
CStreamingAsciiFile* test_file = new CStreamingAsciiFile(test_file_name);
SG_REF(test_file);
CStreamingDenseFeatures<float32_t>* test_features = new CStreamingDenseFeatures<float32_t>(test_file, true, 1024);
SG_REF(test_features);
CMulticlassLabels *pred = cpt->apply_multiclass(test_features);
test_features->reset_stream();
SG_SPRINT("num_labels = %d\n", pred->get_num_labels());
SG_UNREF(test_features);
SG_UNREF(test_file);
test_file = new CStreamingAsciiFile(test_file_name);
SG_REF(test_file);
test_features = new CStreamingDenseFeatures<float32_t>(test_file, true, 1024);
SG_REF(test_features);
CMulticlassLabels *gnd = new CMulticlassLabels(pred->get_num_labels());
test_features->start_parser();
for (int32_t i=0; i < pred->get_num_labels(); ++i)
{
test_features->get_next_example();
gnd->set_int_label(i, test_features->get_label());
test_features->release_example();
}
test_features->end_parser();
int32_t n_correct = 0;
for (index_t i=0; i < pred->get_num_labels(); ++i)
{
if (pred->get_int_label(i) == gnd->get_int_label(i))
n_correct++;
//SG_SPRINT("%d-%d ", pred->get_int_label(i), gnd->get_int_label(i));
}
SG_SPRINT("\n");
SG_SPRINT("Multiclass Accuracy = %.2f%%\n", 100.0*n_correct / gnd->get_num_labels());
SG_UNREF(train_features);
SG_UNREF(test_features);
SG_UNREF(train_file);
SG_UNREF(test_file);
SG_UNREF(cpt);
SG_UNREF(pred);
exit_shogun();
return 0;
}