Using the Matlab C++ Engine SDK to connect to matlab from within library built with the c++ clibgen workflow

Hello All,

I have a library written in c++ (dll on windows) that I use with the clib generation workflow to create a clib interface to the library.

This works good - but lacks some things (namely printing to the matlab console when running functions).

I started to use the matlab C++ Engine sdk inside the dll library. (using the matlab sdk headers). And I during testing - I am unable to connect to a shared matlab instance. it gives an error ("unable to connect to matlab session") when calling

auto matlabEngine = matlab::engine::connectMATLAB(u"MATLAB_27404");

Using the python engine sdk I can connect to the same instance just fine.

I suspect that it might be because I am trying to connect from within a dll that is bound to the matlab instance I am trying to connect to (via the clib interface).

Is there a known way to do this without some sort of proxy application etc?

Thanks in advance for any Tips/Help,

-Trevor

[Michele]

Hello Trevor,

I think I am having the same problem here (just got there the other way around, first using the matlab engine from a C++ application, which was working fine, then found this issue when building it into a dll and loading it with clib). Did you by any chance get to solve this? Or found a definite answer on whther this is possible at all or not? And if not, could you comment on any alternative approaches you have taken?

Thanks!

Answer 1

[Divyanshu]

Hi Trevor,

You can refer the following documentation which explains about how to call MATLAB from C++ and exchange the data between MATLAB and C++ programs:

https://www.mathworks.com/help/matlab/calling-matlab-engine-from-cpp-programs.html

Additionally, you can refer the following MATLAB Answer thread specifically for the issue of not being able to connect to existing shared MATLAB session:

https://www.mathworks.com/matlabcentral/answers/794182-c-application-cannot-find-or-connect-to-existing-shared-matlab-session