VW::shared_feature_merger Namespace Reference

Classes
struct	sfm_data

Functions
bool	use_reduction (config::options_i &options)
template<bool is_learn>
void	predict_or_learn (sfm_data &, LEARNER::multi_learner &base, multi_ex &ec_seq)
LEARNER::base_learner *	shared_feature_merger_setup (config::options_i &options, vw &all)

Variables
static const std::vector< std::string >	option_strings

Function Documentation

predict_or_learn()

template<bool is_learn>

void VW::shared_feature_merger::predict_or_learn	(	sfm_data &	,
		LEARNER::multi_learner &	base,
		multi_ex &	ec_seq
	)

Definition at line 34 of file shared_feature_merger.cc.

References LabelDict::add_example_namespaces_from_example(), example_predict::begin(), LabelDict::del_example_namespaces_from_example(), CB::ec_is_example_header(), LEARNER::learner< T, E >::learn(), example::pred, LEARNER::learner< T, E >::predict(), and THROW.

{
  if (ec_seq.size() == 0)
    THROW("cb_adf: At least one action must be provided for an example to be valid.");

  multi_ex::value_type shared_example = nullptr;

  const bool has_example_header = CB::ec_is_example_header(*ec_seq[0]);
  if (has_example_header)
  {
    shared_example = ec_seq[0];
    ec_seq.erase(ec_seq.begin());
    // merge sequences
    for (auto& example : ec_seq) LabelDict::add_example_namespaces_from_example(*example, *shared_example);
    std::swap(ec_seq[0]->pred, shared_example->pred);
  }
  if (ec_seq.size() == 0)
    return;
  if (is_learn)
    base.learn(ec_seq);
  else
    base.predict(ec_seq);

  if (has_example_header)
  {
    for (auto& example : ec_seq) LabelDict::del_example_namespaces_from_example(*example, *shared_example);
    std::swap(shared_example->pred, ec_seq[0]->pred);
    ec_seq.insert(ec_seq.begin(), shared_example);
  }
}

shared_feature_merger_setup()

LEARNER::base_learner * VW::shared_feature_merger::shared_feature_merger_setup	(	config::options_i &	options,
		vw &	all
	)

Definition at line 65 of file shared_feature_merger.cc.

References LEARNER::as_multiline(), LEARNER::init_learner(), LEARNER::make_base(), setup_base(), and use_reduction().

Referenced by parse_reductions().

{
  if (!use_reduction(options))
    return nullptr;

  auto data = scoped_calloc_or_throw<sfm_data>();

  auto* base = LEARNER::as_multiline(setup_base(options, all));
  auto& learner = LEARNER::init_learner(data, base, predict_or_learn<true>, predict_or_learn<false>);

  // TODO: Incorrect feature numbers will be reported without merging the example namespaces from the
  //       shared example in a finish_example function. However, its too expensive to perform the full operation.

  return LEARNER::make_base(learner);
}

use_reduction()

bool VW::shared_feature_merger::use_reduction

(

config::options_i &

options

)

Definition at line 19 of file shared_feature_merger.cc.

References VW::config::options_i::was_supplied().

Referenced by shared_feature_merger_setup().

{
  for (const auto& opt : option_strings)
  {
    if (options.was_supplied(opt))
      return true;
  }
  return false;
}

Variable Documentation

option_strings

const std::vector<std::string> VW::shared_feature_merger::option_strings

static

Initial value:

= {
    "csoaa_ldf", "wap_ldf", "cb_adf", "explore_eval", "cbify_ldf", "cb_explore_adf", "warm_cb"}

Definition at line 16 of file shared_feature_merger.cc.