how to call matrix from workspace into simulink and return it in workspace?

Hi

How can I call a matrix from workspace in matlab into simulink and do some mathematical operations on it and return it in matlab workspace?

for example:

I use "simin" block in simulink to get the matrix A=[1 2 3], then with a "matlab function" block I want to get the size of the matrix A the matrix and finally using a "simout" block I want to export the size of A into the workspace, but it doesn't work.

I have also attached the screenshot.

Can someone help please?

Answer 1

[Rajanya]

Hi @Saeed Ahmadzadeh Mahboobi,

The error is likely in the definition of the function in the MATLAB function block itself since 'B' is never defined in the function. Output arguments need to be fully defined for code generation. Also, since 'B' (which is supposed to be the output of the function) is never defined, Simulink fails to determine the size and type of output from the MATLAB function block, leading to such errors.

Changing the function definition to the following will remove the errors:

function B = fcn(A)
%#codegen
u=size(A);
B = u(1,1)+u(1,2); 

I hope this helps. Thanks.