SubSystem block does not have a parameter named 'MATLABFunction'

% Create a new Simulink model
modelName = 'mySimulinkModel';
new_system(modelName);
open_system(modelName);

% Add a MATLAB Function block to the model
blockPath = [modelName, '/MyMATLABFunction'];
add_block('simulink/User-Defined Functions/MATLAB Function', blockPath);

% Set the function code in the MATLAB Function block
functionCode = sprintf('function y = fcn(u)\n    y = u^2;\nend');
set_param(blockPath, 'MATLABFunction', functionCode);

% Optionally, set block position
set_param(blockPath, 'Position', [100, 100, 200, 150]);

% Save and close the model
save_system(modelName);
close_system(modelName);

Answer 1

[Paul]

The function code in the Matlab Function block can be modified programatically using MATLABFunctionConfiguration