.m file with ifdef (ifdef 기능을 활용한 .m파일 구성)

Sorry, I fixed my Question "Stateflow(x) --> Other C file(*.c)

Hello! I want some help.

I'm making a model and using 'Code Generation' in C language.

And I'm managing my model's variable in .m file!

I want to use ifdef, like C code, to manage two value with one variable in .m file.

example)

ifdef a

length1 = 30;

else

length1 = 40;

endif

And that 'a' is comming from other .c file.

I want to set the 'a' with my hand code.(.c) according to the situation.

If it possible, how can I make it?

thank you!

안녕하세요.

혹시 .m 파일에 c 코드의 ifdef 함수와 같은 기능을 써서 한 개의 파라미터를 조건에 따라 값을 변경하여 쓰고 싶은데

이게 가능한 것인지 궁금합니다. (예제는 위의 example)과 같습니다.)

ifdef에 대한 조건 값(a)는 같은 프로젝트의 다른 .c 파일에서 정의해주었으면 합니다.

커뮤니티 질문글에 관련 정보를 찾을 수 없어 글을 남깁니다....

감사합니다.

[Angelo Yeo]

I deleted my previous answer because your change has made the question very different from the first one. Can you elaborate your question further? How are you going to use the C file? Do you want to use Simulink? Can you provide a simple C code and provide your workflow in detail?

[성욱]

Ok

I made a model in Stateflow and generate it in C code.

And this model is used in various project, but the parameter is a little bit different.

So, I figure out that if I make a .m file like this,(down below) It could be more easier.

(Oh..... I wrote upper example with mistake.... I should write #ifdef #endif....)

#ifdef (project_name)

length1 = 30;

length2 = 10;

#endif

#ifdef (project_name)

length1 = 40;

length2 = 20;

#endif

Because, I can make a .c file which defines (project_name) on it.

than just bring that variable into .m file.

As a result, the parameter would be set according to the Project.

My Question is how can I bring the (project_name) into my .m file.

(Sorry, I have nothing to do with Simulink)

[Angelo Yeo]

Do you want to get the name of current project? Like the one below?

https://www.mathworks.com/help/matlab/ref/currentproject.html

How do you define your "project'?

Answer 1

[Ayush]

Hi 성욱,

In MATLAB, you can use conditional statements like `if-else` to achieve similar functionality to `#ifdef` in C. However, you cannot directly define a variable in an `.m` file based on a condition set in another `.c` file.

If you want to set the value of a variable in MATLAB based on a condition set in a C file, you can try out the below mentioned options:

1. Pass the value from the C file to MATLAB: You can use MATLAB's External Interfaces to call C functions from MATLAB. In your C code, you can set the value of `a` and pass it to MATLAB as a function argument.

2. Use a configuration file: Instead of directly setting the value in the C file, you can create a configuration file (e.g., a text file) that contains the value of `a`. Then, in your MATLAB code, you can read the configuration file and set the value of `length1` accordingly.

Here's an example of how you can achieve this using a configuration file:

C code (config.txt):

a = 2;

MATLAB code

% Read the configuration file
configFile = 'config.txt';
fileID = fopen(configFile, 'r');
C = textscan(fileID, '%s %d', 'Delimiter', '=');
fclose(fileID);

% Get the value of 'a' from the configuration file
a = C{2};

% Set the value of 'length1' based on 'a'
if a == 1
    length1 = 30;
else
    length1 = 40;
end

Remember to update the `config.txt` file manually according to the situation before running the MATLAB code.