# Input and output with Harwell-Boeing and Matrix Market formats¶

Including the file gmm/gmm_inoutput.h you will be able to load and save matrices with Harwell-Boeing and Matrix Market formats. Concerning the Harwell-Boeing format, only the type gmm::csc_matrix<double> and gmm::csc_matrix<std::complex<double> > has been interfaced, so you can execute:

gmm::Harwell_Boeing_save("filename", A); // save the matrix A .

If A is not a gmm::csc_matrix<double> or a gmm::csc_matrix<std::complex<double> > a copy is made.
Concerning the Matrix Market format, it is possible to save a gmm::csc_matrix<double> or a gmm::csc_matrix<std::complex<double> > and to load a gmm::row_matrix<VECT> or a gmm::col_matrix<VECT>:
gmm::MatrixMarket_save("filename", A); // save a csc_matrix.