MATLAB: Does the MEX file that used to work before R2017a now crash MATLAB

crashMATLABmexr2017a

I wrote a MEX file a few years ago and it worked fine in MATLAB. After upgrading to MATLAB R2017a and recompiling the MEX file, however, it now crashes MATLAB on execution. What has changed that would cause this to happen?

Best Answer

In MATLAB R2017a, the mex function uses the large-array-handling API (-largeArrayDims option) by default. If your older MEX file code was written without consideration of this change, it is possible that it will now crash MATLAB.

Best practice is to update your MEX source code to use this library and rebuild the MEX file. For instructions, see:

https://www.mathworks.com/help/releases/R2017a/matlab/matlab_external/upgrading-mex-files-to-use-64-bit-api.html

If you do not update your MEX source code, you can still build your MEX files using the -compatibleArrayDims option. For information about the consequences of using the -compatibleArrayDims option to build MEX files, see:

https://www.mathworks.com/help/releases/R2017a/matlab/matlab_external/what-if-i-do-not-upgrade.html

Related Solutions

MATLAB: Mex command with -largeArrayDims and/or -R2017b

According to the answer of the technical support:

The 64 bit addressing triggered by the -largeArrayDims flag is implicitly enabled by -R2017b already. Although there is no conflict for the actual compilation, the flags are treated as incompatible.

Solution: Use -largeArrayDims for compiling under older Matlab versions, and -R2017b for newer ones:

if verLessThan('matlab', '9.4')  % < R2018a
  mex -largeArrayDims test.c
else                             % >= 2018a
  mex -R2017b test.c
end

Not handy, but working.

MATLAB: I am trying to MEX a fortran file on MAC OS with Xcode 8.2.1. However, when I try to MEX using ‘mex’ command I get the following error: “No supported compiler or SDK was found.

Xcode does not provide a FORTRAN compiler. To compile a FORTRAN file, you need to install one of the following Compilers as they support FORTRAN compilation.

Intel Parallel Studio XE 2016 for Fortran Or

Intel Parallel Studio XE 2015 for Fortran Or

Intel Fortran Composer XE (2013).

Best Answer

Related Solutions

MATLAB: Mex command with -largeArrayDims and/or -R2017b

MATLAB: I am trying to MEX a fortran file on MAC OS with Xcode 8.2.1. However, when I try to MEX using ‘mex’ command I get the following error: “No supported compiler or SDK was found.

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