SimulationMetaData manipulation in Simulink

Hello,

I am looking to manipulate the SimulationMetaData property from Simulink.SimulationOutput object.

I am interested in expanding the UserData property to add custom data.

Tried the PostSimFcn property by registering a callback that modifies the output object, and works fine, but when enabling LoggingToFile option on model settings, the modification is not preserved in the *mat file.

At the end, I would like my output mat file containing simulink results (logsout, yout, etc) and SimulationMetaData containing the modifications made.

Any suggestions?

[Gayathri]

Hey @Isaac De La Cruz,

Can you elaborate more on what function and method you are using. I am asking as when I tried to modify the "UserData" property using "PostSimFcn", I am getting the below error.

Error executing 'PostSimFcn' on SimulationInput object.

Caused by:

Error using postsim

Setting the 'SimulationMetadata' property of class 'Simulink.SimulationOutput' is not supported.

Answer 1

[Sameer]

Hi @Isaac De La Cruz

When "Logging to File" is enabled in Simulink, simulation results are written to the MAT file before any modifications made by "PostSimFcn" are applied. As a result, custom data added in "PostSimFcn" does not appear in the saved file.

As a workaround you can attach custom data after the simulation and then save.

Here's how you can do it:

out = sim(mdl, 'LoggingToFile','on', 'LoggingFileName','out.mat', ...);
out = setUserData(out,myCustomData); % attach your data
save('out_with_metadata.mat','out'); % save combined data+metadata

Hope this helps!

[Isaac De La Cruz]

Hello @Sameer,

Alright! I thought that when the 'LoggingToFile' option is enabled it included also the changes made to the Simulink's output.

Thanks for the clear explanation!