Convert Matlab script in C++ ?

Hello,

I have a Matlab script that I would like to convert in C++, is it possible to do that with Matlab Coder ? Because, when I add my script as an Entry-Point File, I get this message: "All Entry_Point Files must be functions".

Can Matlab Compiler do the conversion from the script to C++ ?

Thank you in advance for your answer.

Fanta C.

[Denis Gurchenkov]

MATLAB Coder does not support scripts (yet). Just make your script into a function.

[Fanta Camara]

Thank you very much for your answer ! Do you know if functions for kinematics calculations from Matlab Robotics toolbox are also supported by Matlab coder ?

[Denis Gurchenkov]

It looks like a number of functions under matlab/toolbox/robotics got MATLAB Coder support in R2015a release (were not supported in earlier releases). If you can name a particular function, I can check that one.

[Fanta Camara]

I am using Link and SerialLink classes and kinematics functions such as fkine and ikine.

I tried to generate C code with R2014b for the forward kinematics and I got the following error message: "Nested functions are not supported by Matlab Coder". I don't understand why I get this error because I don't use any nested function. My function is in attached file, if you can have a look on it please and tell me what is wrong. Thanks a lot.

[Walter Roberson]

Move the lines before the "function" line to after the "function" line.

[Fanta Camara]

Sorry, I don't understand what to do.

[Walter Roberson]

Your file starts with some comment lines and might even have a "clear all" there. Delete those lines. The very first line in your forkin.m should be the line that starts with the word "function". This might possibly prevent the code from being thought to be a nested function.

[Denis Gurchenkov]

MATLAB Coder ignores the comment lines, there is no need to move them down after "function" line, that's not the problem. I ran codegen on your forkin.m and I don't see the "All entry point files must be functions" problem. Did you use some other file, not that one?

Also, I can't fine any functions called Link and SerialLink in MATLAB. Can you please tell me where you got those? Are they part of some third-party library? If you type "which Link" in MATLAB -- it'll tell you where that function comes from.

[Walter Roberson]

My speculation is that there were additional lines of executable code not shown in what was posted.

[Fanta Camara]

Hello, sorry for the delay. Firstly, thank you very much for your replies. Yes, you are right Denis, before it was a script, that's why I couldn't converted it, but now I have a new file with my function. Link and SerialLink are robot manipulator's classes in Matlab Robotics System Toolbox, they are used for the calculation of robot kinematics, etc.

Now,when I try to convert my file, in attached document, with Matlab R2015a, the conversion fails, I still have errors from the Code generation Readiness tool concerning functions and cell arrays that are unsupported. But Link and SerialLink classes can used converted in C++, because they are recognized by the code generation readiness. Thank you.

[Walter Roberson]

I do not see any cell arrays in that routine?

[Fanta Camara]

These errors come from internal functions in the Robotics toolbox such as functions: fieldnames, setfield, getfield, rethrow, sym... the problem is that I don't directly use them.

[Walter Roberson]

You appear to be using the Peter Corke robotics toolkit, tested against R2011b at latest, with no support. It was not designed for code generation. The Robotics Toolkit that Mathworks supports for code generation is their Robotics Systems Toolkit which supports deploying under their ROS (Robotic Operating System).

(I note by the way that Peter has placed his code in github at https://github.com/petercorke/robotics-toolbox-matlab -- but that version does use cell arrays as well)

It is common for generalized packages to support options processing by way of optional fields in structures. Unfortunately that interface is not compatible with code generation, as C and C++ structures must have fixed fields.

[Fanta Camara]

You are right, I am using Peter Corke toolbox because I tought Peter Corke Robotics Toolbox was the same as Matlab Robotics Toolbox. Do you think that I can generate C code with Matlab toolbox without using Simulink ? And can I use the ROS under Windows ? Because at the end, I will integrate the generated C code to my Visual C++ project. Thank you very much Walter.

[Walter Roberson]

http://www.mathworks.com/help/coder/ug/functions-supported-for-code-generation--categorical-list.html does not list any functions in the Robotic Systems Toolbox, the functions of which are listed http://www.mathworks.com/help/robotics/functionlist.html

The code generation I see for it appears to be limited to Simulink

It is supported by MATLAB Compiler, but that does not generate code. On the other hand, with MATLAB Compiler SDK you can use Compiled functions with .NET (this is not code generation; the MATLAB engine is called upon to do the work.)

[Fanta Camara]

Thank you so much. You mean I can use Matlab Compiler with Peter Corke's robotics toolbox too ?

[Denis Gurchenkov]

Yes, you should be able to use Matlab Compiler with Peter's toolbox.

[Fanta Camara]

Oh, that would be cool. Thank you !

[Walter Roberson]

Just keep in mind that the Compiler produces a .exe or .dll not code.

[Fanta Camara]

Yes, I understand. I would like to use Matlab Compiler SDK with should create an header file that I can integrate to C++ code. But is it possible the executable returns some values ? Because in Matlab, my function returns a matrix, and I wonder if it will be the same with the executable.

[Walter Roberson]

Yes, you can do that with Compiler SDK

[Fanta Camara]

Ok, thank you very much !

[Steven Lord]

Denis @ 1 Sep 2015 at 11:57,

If this third party robotics toolbox uses Symbolic Math Toolbox, as Fanta's comment @ 31 Aug 2015 at 9:29 suggests, it will NOT be able to be compiled with either MATLAB Compiler or MATLAB Coder.

[Fanta Camara]

The problem is that I don't know if this toolbox uses Symbolic Math Toolbox.

[Fanta Camara]

I don't have Symbolic Math Toolbox on my computer, so I guess the Robotics Toolbox works without using it.

[Walter Roberson]

It appears that with the newly released R2015b, a number of functions in the Robotics Toolkit (the Mathworks one) support code generation. See http://www.mathworks.com/help/coder/ug/functions-supported-for-code-generation--categorical-list.html#buymxey

[Fanta Camara]

Thanks for the information ! Actually, as you suggested I could create an executable from Matlab compiler SDK. I will try now to integrate it to my project. Thank you very much guys for your help!