Generate code: source code or mex file ?

Hi,

it has only been a few days since I am dealing with mex files.

I am using Matlab coder. I can convert my original m files without any problems, but now I've got a doubt on which "build type" to choose. I was, without thinking too much, selecting the "Source code". I got the .mexw64, and I run the function name_function_mex in my Matlab code.

I saw now that, based on the description, the source type "MEX" should be more suitable, because it is a compiled code to be run in Matlab. I also tried the "MEX" built type, and the only difference I see is that I get a lot more files in the generated mex-related folder.

So my question is: why did the "source code" work at all in my case? Since it was working in my Matlab code (I could call the name_function_mex function as any other functions), should I still consider the build type "MEX" for some special reason...?

Answer 1

[Darshan Ramakant Bhat]

From your description I am assuming that you are using coder app.

When the "build type" is "Source code" it is not suppose to generate any MEX files. The correct configuration to generate MEX is the "MEX" build type.

I had tried "Source Code" configuration with a simple example, but I did not get any MEX file generated. Please attach the .prj file along with all the input files so that I can try to reproduce this from my end.

[Maria]

Thank you for your answer. At the moment, I cannot share the code, but I just tried again, and I got the codegen folder -> mex folder and lib folder. In the mex folder, there is another folder with the name of the function I used in Matlab coder. Inside this one, there are 2 folders (html and interface), and the .mexw64.

I will try to write a piece of code such that I can share it with you.

[Darshan Ramakant Bhat]

Ahh, Now I got what is happening.

There is an intermediate optional step called "Check for run-time issues". In this step Coder will generate a MEX file to check run-time issues. More details :

https://in.mathworks.com/help/coder/ug/check-for-run-time-issues-in-the-matlab-coder-app.html

If you skip this step, the "mex" folder should not get generated (not recommended).

So this will create a "mex" folder inside codegen. The .mexw64 is cached inside this folder to avoid re-generation when no settings are changed. Note that this MEX will be generated with customized settings suitable for internal use of runtime issue checking.

When you choose "MEX" build type, a .mexw64 file will be generate outside the "codegen" folder. Please use this in your application.

Hope this will be helpful for you.

[Maria]

Now is clear! Perfect, now I understood! I will use the MEX build type. Thank you very much!