MATLAB: Call a mex file and using coder

code generationmatlab codermex

I have some legacy Matlab code which makes a call to a mex file, call it get_score. The mex file was written in C. This Matlab code was then compiled to C using the mcc command. This was all done on an older version of Matlab.

We are now upgrading to the latest version of Matlab so I will be using Matlab Coder to generate C code from our Matlab code. What is the correct way to call the get_score mex file? I tried running mex on the c code and generating a new mexw32 file and calling that but when I attempt to run coder I get the error Unsupported file extension 'mexw32'.

Is the proper way to do this just compile the C code to a standard dll using, say Visual Studio, and then call the dll using coder.ceval?

Best Answer

The thing about mex files is they require MATLAB to run (MATLAB executable). MATLAB coder can generate more generic c-code that can be utilized independent of MATLAB so if you try to call a mex-file from this code you may run into issues.

It sounds like you already know what to do and you can use the ceval command directly on the C-code that the mex file utilizes.

Related Solutions

MATLAB: How to generate code for mex files too while generating hardware specific code from simulink

Since MEX-files are specific to the MATLAB environment, you cannot run them on an embedded target. If you have the equivalent standalone C code equivalent also, you can use the following code style to call the MEX-file during simulation, and the C-code in the generated code:

function y = myfcn(u)
coder.extrinsic('mymex');
y = 0; %pre-allocate
if coder.target('Sfun')
  y = mymex(u);
else
  y = coder.ceval('foo', u);
end

Please refer to the documentation for more information on coder.target and coder.ceval.

MATLAB: Coder.ceval(‘printf’,….) does not print a message instantaneously

Hi,

as long you stay with mex you can do a

mexEvalString("drawnow");

So a

coder.ceval('mexEvalString', '"drawnow"')

This will give the MATLAB Thread enough time to flush the buffer and to display the data.

In the case you want to generate code not for mex only you can use the coder.target to differentiate between those cases during the code generation process:

if strcmp('mex',coder.target)
    coder.ceval('mexEvalString', '"drawnow"')
end

Best Answer

Related Solutions

MATLAB: How to generate code for mex files too while generating hardware specific code from simulink

MATLAB: Coder.ceva​l(‘printf’​,….) does not print a message instantaneously

Related Question

MATLAB: Coder.ceval(‘printf’,….) does not print a message instantaneously