MulticlassTask Namespace Reference

Classes
struct	task_data

Functions
void	initialize (Search::search &sch, size_t &num_actions, VW::config::options_i &)
void	finish (Search::search &sch)
void	run (Search::search &sch, multi_ex &ec)

Variables
Search::search_task	task = {"multiclasstask", run, initialize, finish, nullptr, nullptr}

Function Documentation

finish()

void MulticlassTask::finish

(

Search::search &

sch

)

Definition at line 34 of file search_multiclasstask.cc.

References v_array< T >::delete_v(), Search::search::get_task_data(), and MulticlassTask::task_data::y_allowed.

{
  task_data* my_task_data = sch.get_task_data<task_data>();
  my_task_data->y_allowed.delete_v();
  delete my_task_data;
}

initialize()

void MulticlassTask::initialize	(	Search::search &	sch,
		size_t &	num_actions,
		VW::config::options_i &
	)

Definition at line 22 of file search_multiclasstask.cc.

References MulticlassTask::task_data::max_label, MulticlassTask::task_data::num_level, v_array< T >::push_back(), Search::search::set_num_learners(), Search::search::set_options(), Search::search::set_task_data(), and MulticlassTask::task_data::y_allowed.

{
  task_data* my_task_data = new task_data();
  sch.set_options(0);
  sch.set_num_learners(num_actions);
  my_task_data->max_label = num_actions;
  my_task_data->num_level = (size_t)ceil(log(num_actions) / log(2));
  my_task_data->y_allowed.push_back(1);
  my_task_data->y_allowed.push_back(2);
  sch.set_task_data(my_task_data);
}

run()

void MulticlassTask::run	(	Search::search &	sch,
		multi_ex &	ec
	)

Definition at line 41 of file search_multiclasstask.cc.

References v_array< T >::begin(), Search::search::get_task_data(), Search::search::loss(), MulticlassTask::task_data::max_label, MulticlassTask::task_data::num_level, Search::search::output(), Search::search::predict(), UINT64_ONE, and MulticlassTask::task_data::y_allowed.

{
  task_data* my_task_data = sch.get_task_data<task_data>();
  size_t gold_label = ec[0]->l.multi.label;
  size_t label = 0;
  size_t learner_id = 0;

  for (size_t i = 0; i < my_task_data->num_level; i++)
  {
    size_t mask = UINT64_ONE << (my_task_data->num_level - i - 1);
    size_t y_allowed_size = (label + mask + 1 <= my_task_data->max_label) ? 2 : 1;
    action oracle = (((gold_label - 1) & mask) > 0) + 1;
    size_t prediction = sch.predict(*ec[0], 0, &oracle, 1, nullptr, nullptr, my_task_data->y_allowed.begin(),
        y_allowed_size, nullptr, learner_id);  // TODO: do we really need y_allowed?
    learner_id = (learner_id << 1) + prediction;
    if (prediction == 2)
      label += mask;
  }
  label += 1;
  sch.loss(!(label == gold_label));
  if (sch.output().good())
    sch.output() << label << ' ';
}

Variable Documentation

task

Search::search_task MulticlassTask::task = {"multiclasstask", run, initialize, finish, nullptr, nullptr}

Definition at line 10 of file search_multiclasstask.cc.