Function EmptyDMatrix

tests/cpp/helpers.h:365–367

Generate an empty DMatrix, mostly for its meta info.

// Generate an empty DMatrix, mostly for its meta info.
inline std::shared_ptr<DMatrix> EmptyDMatrix() {
  return RandomDataGenerator{0, 0, 0.0}.GenerateDMatrix();
}

[[nodiscard]] std::vector<float> GenerateRandomCategoricalSingleColumn(std::size_t n,
                                                                       std::size_t n_categories);