Fortran Source MEX Files

Write Fortran subroutines using MATLAB® API libraries

A MEX file lets you call a Fortran subroutine from MATLAB. To create a MEX file, you need:

For information about writing C/C++ MEX files, see C Source MEX Files.

For information about using the loadlibrary and calllib commands to call functions in shared libraries, see C Libraries.

For information about writing S-functions using Fortran code, see your Simulink® documentation.

MEX files are not appropriate for all applications. MATLAB is a high-productivity environment whose specialty is eliminating time-consuming, low-level programming in compiled languages like Fortran. In general, do your programming in MATLAB. Do not use MEX files unless your application requires it.


Create Fortran Source MEX File

This example shows how to write a MEX file to call a Fortran subroutine, timestwo, in MATLAB using a MATLAB matrix.

Tables of MEX Function Source Code Examples

These tables link to source code for MEX function examples.

Handle Complex Fortran Data

This example shows how to pass complex data to a MEX file using the interleaved complex Fortran Matrix API.

User Messages

To print text in the MATLAB Command Window, use the mexPrintf function.

Error Handling

The mexErrMsgIdAndTxt function prints error information and terminates your binary MEX file.

Components of Fortran MEX File

The gateway routine is the entry point to the MEX file.

MATLAB Fortran API Libraries

The Matrix Library and the MEX Library describe functions you can use in your gateway and computational routines that interact with MATLAB programs and the data in the MATLAB workspace.

Data Flow in Fortran MEX Files

Suppose your MEX-file myFunction has two input arguments and one output argument.

Memory Management

When a MEX function returns control to MATLAB, it returns the results of its computations in the output arguments—the mxArrays contained in the left-side arguments plhs[].

Handling Large mxArrays

Binary MEX-files built on 64-bit platforms can handle 64-bit mxArrays.

Upgrade MEX Files to Use Interleaved Complex API

MATLAB Version 9.4 (R2018a) supports an interleaved representation of complex numbers.

Related Information