Change variables in the base workspace through a Matlab Function block
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I'm trying to change a matrix (of type double) in the base workspace through a Matlab Function block in Simulink. To access the matrix in the base workspace within the Matlab function block, I have set the variable type in the Symbols pane of the Matlab function block to parameter data. Then I change the parameter and assign it to the base workspace with the assignin function, which I found in past solutions for the same problem.
Here is an example of my problem:
function updateBaseWorkspaceVariable(Workplan, TasksToDo)
% Modify the base workspace variable using the parameters
assignin('base', 'myVariable', Workplan + TasksToDo);
However when running my code and this example code I get the following error message:
Error:Function 'assignin' not supported for code generation.
Function 'MATLAB Function' (#343.124.176), line 3, column 5:
"assignin('base', 'myVariable', Workplan + TasksToDo)"
Launch diagnostic report.
Since this is a solution already used in past Matlab versions I'm wondering, if it's a problem within the Matlab version that I'm using (23a) or whether there is something I'm missing.
Thanks in advance for your help!
Jon on 21 Sep 2023
Edited: Jon on 21 Sep 2023
I would suggest using the "Interpreted MATLAB Function" block for this purpose. It doesn't need to get compiled. It is under
Simulink>User-Defined Functions in the Library Browser.
In the Parameters field MATLAB function, enter something like myfun(u).
In a directory that is on the MATLAB path, make and save an .m file called myfun(u), that has your code it in it, e.g.
function y = myfun(u)
y = u^2;
More Answers (1)
Harald on 21 Sep 2023
you can declare a function as extrinsic to address the error message, using coder.extrinsic.
I would question the workflow of writing to the base workspace every time the block is executed. If you only need to have the variable in the workspace after the simulation, you can use model callbacks.