int TreeliteDMatrixCreateFromMat()

in src/c_api/c_api.cc [97:142]

• 42 lines of code
• 6 McCabe index (conditional complexity)

int TreeliteDMatrixCreateFromMat(const float* data,
                                 size_t num_row,
                                 size_t num_col,
                                 float missing_value,
                                 DMatrixHandle* out) {
  const bool nan_missing = common::math::CheckNAN(missing_value);
  API_BEGIN();
  CHECK_LT(num_col, std::numeric_limits<uint32_t>::max())
    << "num_col argument is too big";
  DMatrix* dmat = new DMatrix();
  dmat->Clear();
  auto& data_ = dmat->data;
  auto& col_ind_ = dmat->col_ind;
  auto& row_ptr_ = dmat->row_ptr;
  // make an educated guess for initial sizes,
  // so as to present initial wave of allocation
  const size_t guess_size
    = std::min(std::min(num_row * num_col, num_row * 1000),
               static_cast<size_t>(64 * 1024 * 1024));
  data_.reserve(guess_size);
  col_ind_.reserve(guess_size);
  row_ptr_.reserve(num_row + 1);
  const float* row = &data[0];  // points to beginning of each row
  for (size_t i = 0; i < num_row; ++i, row += num_col) {
    for (size_t j = 0; j < num_col; ++j) {
      if (common::math::CheckNAN(row[j])) {
        CHECK(nan_missing)
          << "The missing_value argument must be set to NaN if there is any "
          << "NaN in the matrix.";
      } else if (nan_missing || row[j] != missing_value) {
        // row[j] is a valid entry
        data_.push_back(row[j]);
        col_ind_.push_back(static_cast<uint32_t>(j));
      }
    }
    row_ptr_.push_back(data_.size());
  }
  data_.shrink_to_fit();
  col_ind_.shrink_to_fit();
  dmat->num_row = num_row;
  dmat->num_col = num_col;
  dmat->nelem = data_.size();  // some nonzeros may have been deleted as NaN

  *out = static_cast<DMatrixHandle>(dmat);
  API_END();
}