Function LGBM_DatasetGetSubset

src/c_api.cpp:921–947

}

int LGBM_DatasetGetSubset(
  const DatasetHandle handle,
  const int32_t* used_row_indices,
  int32_t num_used_row_indices,
  const char* parameters,
  DatasetHandle* out) {
  API_BEGIN();
  auto param = Config::Str2Map(parameters);
  Config config;
  config.Set(param);
  if (config.num_threads > 0) {
    omp_set_num_threads(config.num_threads);
  }
  auto full_dataset = reinterpret_cast<const Dataset*>(handle);
  CHECK(num_used_row_indices > 0);
  const int32_t lower = 0;
  const int32_t upper = full_dataset->num_data() - 1;
  Common::CheckElementsIntervalClosed(used_row_indices, lower, upper, num_used_row_indices, "Used indices of subset");
  if (!std::is_sorted(used_row_indices, used_row_indices + num_used_row_indices)) {
    Log::Fatal("used_row_indices should be sorted in Subset");
  }
  auto ret = std::unique_ptr<Dataset>(new Dataset(num_used_row_indices));
  ret->CopyFeatureMapperFrom(full_dataset);
  ret->CopySubset(full_dataset, used_row_indices, num_used_row_indices, true);
  *out = ret.release();
  API_END();
}

int LGBM_DatasetSetFeatureNames(
  DatasetHandle handle,