Load code for a MATLAB function block at Simulink runtime

Question

I would like to have some file, myfunc.m, in my MATLAB path and somehow load its contents into a MATLAB function block automatically just before the simulation starts. This way, I can use an external editor to write these embedded function, version control them separately as independent files, etc.

Is there a way to achieve this programmatically?

My initial attempt was to try and access the contents of the function block using something like get_param, but I can't seem to gain read/write access to the code itself.

Answer 1

If the target MATLAB Function block doesn't already exist then you can add it as follows (see this SO post):

load_system('eml_lib');
libname = sprintf('eml_lib/MATLAB Function');
add_block(libname,'myModel/myBlockName');

You can then modify the block's code using the Stateflow API:

sf = sfroot();
block = sf.find('Path','myModel/myBlockName','-isa','Stateflow.EMChart');
block.Script = 'Your code goes here';

See also this post on MATLAB Answers.

Answer 2

First, you will need to add the folder containing the m-file to the default path. To do this:

(In the Command window) Go to File -> Set Path -> Add Folder (choose the folder containing the m-file)

Now, you should use the InitFcn callback in the model properties to call your function. To do this, open the model:

(In the Model window) Go to File -> Model Properties -> Callbacks -> InitFcn In the edit box provided for the InitFcn, write the command to call your function i.e. myfunc(); You will have to modify this command as per your function and requirements.

Once done, apply the changes to the Model Properties window and simulate the model.

Answer 3

I am thinking that model callbacks may be a way to do what you want, though I have not used this technique myself.