File I/O (text, binary and HDF5)

All vector‐file operations live in VectorIO.hpp. Two inline functions, read_vector and write_vector, dispatch on the file extension (via get_extension()) to the correct I/O path.

write_vector

inline bool write_vector(
    const std::string &filename,
    const std::vector<double> &vec
);

• Determine the extension of the file and its size

  size_t N = vec.size();
  std::string ext = get_extension(filename);
  

• If the file is a .txt file

  std::ofstream out_file(filename);
  for (size_t i = 0; i < N; ++i) {
      out_file << vec[i] << "\n";
  }
  out_file.close();
  return true;
  

• If the file is a .dat file:

  std::ofstream out_file(filename, std::ios::binary);
  out_file.write(
      reinterpret_cast<const char*>(vec.data()),
      N * sizeof(double)
  );
  out_file.close();
  return true;
  

• If the file is an HDF5 file:

  H5::H5File file(filename, H5F_ACC_TRUNC);
  hsize_t dims[1] = { N };
  H5::DataSpace dataspace(1, dims);
  H5::DataSet dataset = file.createDataSet(
      "d", H5::PredType::NATIVE_DOUBLE, dataspace
  );
  dataset.write(vec.data(), H5::PredType::NATIVE_DOUBLE);
  file.close();
  return true;
  

Any unsupported extension triggers an error message and a false return.

read_vector

inline bool read_vector(
    const std::string &filename,
    size_t N,
    std::vector<double> &vec
);

• Determine the extension of the file and its size

  std::string ext = get_extension(filename);
  

• If the file is a .txt file

  std::ifstream in_file(filename);
  vec.resize(N);
  for (size_t i = 0; i < N; ++i) {
      in_file >> vec[i];
      if (in_file.fail()) return false;
  }
  in_file.close();
  return true;
  

• If the file is a .dat file:

  std::ifstream in_file(filename, std::ios::binary);
  vec.resize(N);
  in_file.read(reinterpret_cast<char*>(vec.data()), N * sizeof(double));
  if (in_file.gcount() != static_cast<std::streamsize>(N * sizeof(double)))
      return false;
  in_file.close();
  return true;
  

• If the file is an HDF5 file:

  H5::H5File file(filename, H5F_ACC_RDONLY);
  H5::DataSet dataset = file.openDataSet(ds_name);
  dataset.read(vec.data(), H5::PredType::NATIVE_DOUBLE);
  file.close();
  return true;
  

On any unsupported extension or I/O error, an error is logged to std::cerr and the function returns false.

---

These helpers are invoked by generateVectors.cpp when producing the input files and by vectorSum.cpp when reading and writing vectors for the sum operation.