matfileTutorial.cc

This tutorial shows how to export and import data from Concepts to files in Matlab's binary format.

1. Commented Program
   1. Preparations
   2. Export data from Concepts to a matfile
   3. Import data to Concepts from a matfile
2. Complete Source Code

Commented Program

Include files for input/output handling and matrices.

#include "matfile.hh"
#include "operator.hh"

Preparations

In the first lines two matrices are initialized.

    concepts::DenseMatrix<Cmplx> matrix1(5,3);
    concepts::SparseMatrix<Real> matrix2(4,4);
    for(uint i=0; i<matrix1.dimX(); ++i){
      for(uint j=0; j<matrix1.dimY(); ++j){
        matrix1(i,j) = std::complex<double>(std::rand(),std::rand());
      }
    }
    for(uint i=0;i<std::min(matrix2.dimX(),matrix2.dimY());++i)
      matrix2(i,i) = std::rand();

Export data from Concepts to a matfile

Now we want to write these two matrices into a binary Matlab file. First, we create a concepts::MatfileIO with the designated filename as string input.

    concepts::MatfileIO mo("MatfileIO");

Then we use the method add to add data to the created matfile

    mo.add(matrix1,"Matrix1");
    mo.add(matrix2,"Matrix2");

where we specify the variable name of the data. Finally, we close the matfile.

    mo.close();

Import data to Concepts from a matfile

Now we want to (re-)import the matrices from the matfile. We open the matfile

    concepts::MatfileIO mi("MatfileIO");

and check the properties of the variable Matrix1.

    std::cout << "exists(Matrix1):   " << mi.exists("Matrix1") << std::endl;
    std::cout << "isScalar(Matrix1): " << mi.isScalar("Matrix1") << std::endl;
    std::cout << "isDense(Matrix1):  " << mi.isDense("Matrix1") << std::endl;
    std::cout << "isSparse(Matrix1): " << mi.isSparse("Matrix1") << std::endl;
    std::cout << "isUint(Matrix1):   " << mi.isUint("Matrix1") << std::endl;
    std::cout << "isInt(Matrix1):    " << mi.isInt("Matrix1") << std::endl;
    std::cout << "isReal(Matrix1):   " << mi.isReal("Matrix1") << std::endl;
    std::cout << "isCmplx(Matrix1):  " << mi.isCmplx("Matrix1") << std::endl;

We read the two matrices from the matfile making sure that they exist and have the correct properties.

    concepts::DenseMatrix<Cmplx> matrix1_input;
    if ((mi.exists("Matrix1")) && (mi.isDense("Matrix1")) && (mi.isCmplx("Matrix1")))
      mi.get(matrix1_input,"Matrix1");
    concepts::SparseMatrix<Real> matrix2_input;
    if ((mi.exists("Matrix2")) && (mi.isSparse("Matrix2")) && (mi.isReal("Matrix2")))
      mi.get(matrix2_input,"Matrix2");

We close the matfile.

    mi.close();

Finally, we print the exported and imported matrices on the screen.

    std::cout << std::endl << "Matrix1 (exported) = " << matrix1       << std::endl;
    std::cout << std::endl << "Matrix1 (imported) = " << matrix1_input << std::endl;
    std::cout << std::endl << "Matrix2 (exported) = " << matrix2       << std::endl;
    std::cout << std::endl << "Matrix2 (imported) = " << matrix2_input << std::endl;  

Complete Source Code

Author

Dirk Klindworth 2014

#include "matfile.hh"
#include "operator.hh"
 
 
using concepts::Real;
using concepts::Cmplx;
 
int main(int argc, char** argv) {
 
  try {
    
    // ** preparations **
    concepts::DenseMatrix<Cmplx> matrix1(5,3);
    concepts::SparseMatrix<Real> matrix2(4,4);
    for(uint i=0; i<matrix1.dimX(); ++i){
      for(uint j=0; j<matrix1.dimY(); ++j){
        matrix1(i,j) = std::complex<double>(std::rand(),std::rand());
      }
    }
    for(uint i=0;i<std::min(matrix2.dimX(),matrix2.dimY());++i)
      matrix2(i,i) = std::rand();
    
    // ** write matrices to matfile **
    concepts::MatfileIO mo("MatfileIO");
    mo.add(matrix1,"Matrix1");
    mo.add(matrix2,"Matrix2");
    mo.close();
    
    // ** read matfile **
    concepts::MatfileIO mi("MatfileIO");
    std::cout << "exists(Matrix1):   " << mi.exists("Matrix1") << std::endl;
    std::cout << "isScalar(Matrix1): " << mi.isScalar("Matrix1") << std::endl;
    std::cout << "isDense(Matrix1):  " << mi.isDense("Matrix1") << std::endl;
    std::cout << "isSparse(Matrix1): " << mi.isSparse("Matrix1") << std::endl;
    std::cout << "isUint(Matrix1):   " << mi.isUint("Matrix1") << std::endl;
    std::cout << "isInt(Matrix1):    " << mi.isInt("Matrix1") << std::endl;
    std::cout << "isReal(Matrix1):   " << mi.isReal("Matrix1") << std::endl;
    std::cout << "isCmplx(Matrix1):  " << mi.isCmplx("Matrix1") << std::endl;
    
    // ** load matrices from matfile **
    concepts::DenseMatrix<Cmplx> matrix1_input;
    if ((mi.exists("Matrix1")) && (mi.isDense("Matrix1")) && (mi.isCmplx("Matrix1")))
      mi.get(matrix1_input,"Matrix1");
    concepts::SparseMatrix<Real> matrix2_input;
    if ((mi.exists("Matrix2")) && (mi.isSparse("Matrix2")) && (mi.isReal("Matrix2")))
      mi.get(matrix2_input,"Matrix2");
    mi.close();
      
    // ** output of program **
    std::cout << std::endl << "Matrix1 (exported) = " << matrix1       << std::endl;
    std::cout << std::endl << "Matrix1 (imported) = " << matrix1_input << std::endl;
    std::cout << std::endl << "Matrix2 (exported) = " << matrix2       << std::endl;
    std::cout << std::endl << "Matrix2 (imported) = " << matrix2_input << std::endl;  
    
  }
  catch(concepts::ExceptionBase& e) {
    std::cout << e << std::endl;
    return 1;
  }
}