External Interfaces/API

Exporting Data from MATLAB

There are several methods for getting MATLAB data back to the outside world:

• Create a diary file.

• For small matrices, use the diary command to create a diary file and display the variables, echoing them into this file. You can use your text editor to manipulate the diary file at a later time. The output of diary includes the MATLAB commands used during the session, which is useful for inclusion into documents and reports.

• Use the Save command.

• Save the data in ASCII form using the save command with the -ascii option. For example,

  A = rand(4,3);

  save temp.dat A -ascii

  creates an ASCII file called temp.dat containing

  • 1.3889088e-001  2.7218792e-001  4.4509643e-001
    2.0276522e-001  1.9881427e-001  9.3181458e-001
    1.9872174e-001  1.5273927e-002  4.6599434e-001
    6.0379248e-001  7.4678568e-001  4.1864947e-001
    

  The -ascii option supports two-dimensional double and character arrays only. Multidimensional arrays, cell arrays, and structures are not supported.

  See the save function reference page for more information.

• Use MATLAB I/O functions.

• Write the data in a special format using fopen, fwrite, and the other low-level I/O functions. This method is useful for writing data files in the file formats required by other applications.

• Develop a MEX-file to write the data.

• You can develop a MEX-file to write the data. This is the method of choice if subroutines are already available for writing data files in the form needed by other applications. See the section, Introducing MEX-Files, for more information.

• Translate data from a MAT-file.

• You can write out the data as a MAT-file using the save command. You can then write a program in C or Fortran to translate the MAT-file into your own special format. See the section, Reading and Writing MAT-Files, for more information.

Importing Data to MATLAB

Exchanging Data Files Between Platforms