Function CreateMulticlass

src/boosting/prediction_early_stop.cpp:25–52

}

PredictionEarlyStopInstance CreateMulticlass(const PredictionEarlyStopConfig& config) {
  // margin_threshold will be captured by value
  const double margin_threshold = config.margin_threshold;

  return PredictionEarlyStopInstance{
    [margin_threshold](const double* pred, int sz) {
    if (sz < 2) {
      Log::Fatal("Multiclass early stopping needs predictions to be of length two or larger");
    }

    // copy and sort
    std::vector<double> votes(static_cast<size_t>(sz));
    for (int i = 0; i < sz; ++i) {
      votes[i] = pred[i];
    }
    std::partial_sort(votes.begin(), votes.begin() + 2, votes.end(), std::greater<double>());

    const auto margin = votes[0] - votes[1];

    if (margin > margin_threshold) {
      return true;
    }

    return false;
  },
    config.round_period
  };
}

PredictionEarlyStopInstance CreateBinary(const PredictionEarlyStopConfig& config) {
  // margin_threshold will be captured by value