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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 examples, see Tables of MEX Function Source Code Examples.

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.

Topics

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.

Handle Complex Fortran Data

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

Pass Separate Complex Numbers to Fortran Functions

Write MEX functions in MATLAB R2017b and earlier to call LAPACK or BLAS functions.

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 Fortran Matrix API and the Fortran MEX API 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 Fortran MEX Files to use 64-bit API

Upgrade Fortran MEX files to use 64-bit API.

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