Method BoostFromAverage

src/boosting/gbdt.cpp:354–376

}

double GBDT::BoostFromAverage(int class_id, bool update_scorer) {
  // boosting from average label; or customized "average" if implemented for the current objective
  if (models_.empty() && !train_score_updater_->has_init_score() && objective_function_ != nullptr) {
    if (config_->boost_from_average || (train_data_ != nullptr && train_data_->num_features() == 0)) {
      double init_score = ObtainAutomaticInitialScore(objective_function_, class_id);
      if (std::fabs(init_score) > kEpsilon) {
        if (update_scorer) {
          train_score_updater_->AddScore(init_score, class_id);
          for (auto& score_updater : valid_score_updater_) {
            score_updater->AddScore(init_score, class_id);
          }
        }
        Log::Info("Start training from score %lf", init_score);
        return init_score;
      }
    } else if (std::string(objective_function_->GetName()) == std::string("regression_l1")
               || std::string(objective_function_->GetName()) == std::string("quantile")
               || std::string(objective_function_->GetName()) == std::string("mape")) {
      Log::Warning("Disabling boost_from_average in %s may cause the slow convergence", objective_function_->GetName());
    }
  }
  return 0.0f;
}

bool GBDT::TrainOneIter(const score_t* gradients, const score_t* hessians) {
   GBDT::TrainOneIter_old(gradients, hessians);