Teuchos_MatrixMarket_Raw_Writer.hpp

// @HEADER
// *****************************************************************************
//          Tpetra: Templated Linear Algebra Services Package
//
// Copyright 2008 NTESS and the Tpetra contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER

#ifndef __Teuchos_MatrixMarket_Raw_Writer_hpp
#define __Teuchos_MatrixMarket_Raw_Writer_hpp

#include <Teuchos_SetScientific.hpp>
#include "Teuchos_ArrayView.hpp"
#include "Teuchos_ParameterList.hpp"
#include <fstream>
#include <iostream>

namespace Teuchos {
  namespace MatrixMarket {
    namespace Raw {
      template<class ScalarType, class OrdinalType>
      class Writer {
      public:
  void
        writeFile (const std::string& filename,
       const ArrayView<const OrdinalType>& rowptr,
       const ArrayView<const OrdinalType>& colind,
       const ArrayView<const ScalarType>& values,
       const OrdinalType numRows,
       const OrdinalType numCols)
        {
          std::ofstream out (filename.c_str ());
          TEUCHOS_TEST_FOR_EXCEPTION(! out, std::runtime_error,
            "Failed to open file \"" << filename << "\" for writing.");
          write (out, rowptr, colind, values, numRows, numCols);
        }

  void
        write (std::ostream& out,
         const ArrayView<const OrdinalType>& rowptr,
         const ArrayView<const OrdinalType>& colind,
         const ArrayView<const ScalarType>& values,
         const OrdinalType numRows,
         const OrdinalType numCols)
        {
          using std::endl;
          typedef ScalarTraits<ScalarType> STS;
    typedef typename ArrayView<const OrdinalType>::size_type size_type;

    // Make the output stream write floating-point numbers in
    // scientific notation.  It will politely put the output
    // stream back to its state on input, when this scope
    // terminates.
    Teuchos::SetScientific<ScalarType> sci (out);

    // Data type string for ScalarType.
    std::string dataType;
    if (STS::isComplex) {
      dataType = "complex";
    } else if (STS::isOrdinal) {
      dataType = "integer";
    } else {
      dataType = "real";
    }

          // Print the Matrix Market banner line.  We assume
          // nonsymmetric storage ("general").
          out << "%%MatrixMarket matrix coordinate " << dataType << " general"
        << endl;

          // // Print comments (the matrix name and / or description).
          // if (matrixName != "") {
          //   printAsComment (out, matrixName);
    // }
          // if (matrixDescription != "") {
          //   printAsComment (out, matrixDescription);
    // }

          // Write the dimensions of the sparse matrix: (# rows, #
          // columns, # matrix entries (counting duplicates as
          // separate entries)).
    out << numRows << " " << numCols << " " << rowptr[numRows] << endl;

    for (size_type i = 0; i < numRows; ++i) {
      for (OrdinalType k = rowptr[i]; k < rowptr[i+1]; ++k) {
        const OrdinalType j = colind[k];
        const ScalarType& A_ij = values[k];

        // Matrix Market files use 1-based row and column indices.
        out << (i+1) << " " << (j+1) << " ";
        if (STS::isComplex) {
    out << STS::real (A_ij) << " " << STS::imag (A_ij);
        } else {
    out << A_ij;
        }
        out << endl;
      }
    }
        }
      }; // end of class Writer
    } // namespace Raw
  } // namespace MatrixMarket
} // namespace Teuchos

#endif // __Teuchos_MatrixMarket_Raw_Writer_hpp