MATLAB mex not looking for compiler gfortran on macOS

Hi,

I need to call some Fortran code from within MATLAB. I did some research and read about the mex command and how to use it. Sadly I'm already failing at getting the Fortran compiler to work.

First of all, here's my setup:

 - macOS Sierra 10.12.1 (latest version)
 - MATLAB R2016b (latest version)
 - gfortran 4.9.2 (installed via .dmg from official GNU site)

According to the MATLAB documentation, I can use

    mex -setup FORTRAN

to prepare mex for building a mex-file from Fortran. However, running the command in verbose mode yields the following output:

    Verbose mode is on.
    ... Looking for compiler 'Intel Fortran Composer XE' ...
    ... Looking for environment variable 'IFORT_COMPILER16' ...No.
    ... Looking for environment variable 'IFORT_COMPILER15' ...No.
    ... Looking for environment variable 'IFORT_COMPILER14' ...No.
    ... Looking for environment variable 'IFORT_COMPILER13' ...No.
    ... Executing command 'which ifort' ...No.
    Did not find installed compiler 'Intel Fortran Composer XE'.
    Error using mex
    No supported compiler or SDK was found. For options, visit
    http://www.mathworks.com/support/compilers/R2016b/maci64.html.

Following the link to the MATLAB documentation, one can see that MATLAB does support GNU gfortran 4.9.x on Linux. On Mac however, only Intel's commercial compilers are listed as supported. That's what mex seems to be looking for as well.

Since Mac can also use gfortran to compile Fortran code I thought it'd be possible to get it to work with MATLAB. I've also googled alot and found questions like this one on the MathWorks forum, which suggests that MATLAB should be able to use gfortran, even on Mac.

That's what I think is strange, my MATLAB isn't even looking for a gfortran compiler. All it does is look for an Intel compiler, can't find one and then throws above stated error message.

Regarding my gfortran installation: It is definitely 4.9.2 (which is listed as supported under Linux), which gfortran returns /usr/local/bin and I can successfully compile programs via Terminal.

By the way,

    mex -setup ANY

successfully lists the compilers for C and C++ but no Fortran.

    MEX configured to use 'Xcode with Clang' for C language compilation.
    Warning: The MATLAB C and Fortran API has changed to support MATLAB
   variables with more than 2^32-1 elements. In the near future
   you will be required to update your code to utilize the
   new API. You can find more information about this at:
   http://www.mathworks.com/help/matlab/matlab_external/upgrading-mex-files-to-use-64-bit-api.html.
    MEX configured to use 'Xcode Clang++' for C++ language compilation.
    Warning: The MATLAB C and Fortran API has changed to support MATLAB
   variables with more than 2^32-1 elements. In the near future
   you will be required to update your code to utilize the
   new API. You can find more information about this at:
   http://www.mathworks.com/help/matlab/matlab_external/upgrading-mex-files-to-use-64-bit-api.html.

    To choose a different C compiler, select one from the following:
    Xcode with Clang  mex -setup:'/Users/Lennart/Library/Application Support/MathWorks/MATLAB/R2016b/mex_C_maci64.xml' C
    Xcode Clang++  mex -setup:'/Users/Lennart/Library/Application Support/MathWorks/MATLAB/R2016b/mex_C++_maci64.xml'

I also had a look at those .xml files mentioned at the very end of the last output. There was no file for anything having to do with Fortran and I wasn't able to successfully write one myself. I'm not even sure whether that's the problem...

So simply put my question is: How can I get MATLAB to actually look for and then of course also find my gfortran compiler to use it to compile mex files?

Appreciate your help!

[Lennart Reiher]

I was able to resolve my problem. For further information head over to this StackOverflow post.

Answer 1

[Robert]

As a long time MATLAB user (since 3.0) I am baffled by the decision for Mathworks to disable mex with GNU FORTRAN support under MacOS and to force the power users to jump through hoops and modify xml files to get the compiler to work. Why Mathworks? Why?