'Dot indexing not supported' error shows up only when running executable

Hey,

I see this 'Dot indexing is not supported for variables of this type' error only when running an excutable created from a matlab script. I don't see such error when executing the matlab script itself.

I figured out this snippet here was causing the error. When I comment it out in the matlab script and create an executable, the executable runs fine.

Please, help with this error. Thanks. Also, I use MATLAB 2020b.

[Rik]

Maybe it is the dynamic indexing that is causing problems? That should be relatively easy to determine.

[Sujit Tripathy]

Thanks, Rik, for your response. What does not make sense is I only see the error when running the exceutable, not the matlab script.

Next, I removed indexing:

I still see the error.

[Walter Roberson]

Some level is [] when you expect it to be a struct

[Sujit Tripathy]

Thanks, Walter. You are right. 'mdl' is a linear regression model and "Coefficients" is a property of the linear regression model "mdl".

I updated my scripts to the following now:

The field 'Model' has the linear regression model. Now, I am reading in the linear regression model using a temporary variable and accessing the property "Coefficients" as shown above.

Here are fields of 'Data.ID_000000.linear.Pest.ID_001122 ':

I still see the error though after creating the executable.

[Walter Roberson]

Are you trying to train a model inside a .exe ? Most training functions cannot be compiled (some can be compiled.)

[Sujit Tripathy]

No. I am simply trying to extract model cofficients. Thanks.

Answer 1

[Steven Lord]

Let me guess, you're calling load to load the LinearModel object from a MAT-file. Please see the Tip in the "Fixing Callback Problems: Missing Functions" section on this documentation page. When MATLAB Compiler analyzed your code to determine what needed to be included in the MCR, there was no indication in the code itself that it needed to include the definition of the LinearModel class in the application. Therefore it didn't, and when you called load the application didn't know how to turn the loaded data into an instance of the object.

If you use the -a argument or the %#function pragma to tell MATLAB Compiler that it needs to include the class definition in the application, when you load the object from the MAT-file the application will know the "recipe" for turning that data back into an object.

[Sujit Tripathy]

Thanks, Steven. Where do I locate the class definition for 'LinearModel' class? I am sorry I am new to this.

[Walter Roberson]

%#function LinearModel

might be enough.

[Steven Lord]

If you created the LinearModel object using fitlm or stepwiselm as stated on the documentation page telling MATLAB to include that function in your application may be sufficient. I have not tried this, though.

%#function fitlm
%#function stepwiselm

Or you may be able to just include the class definition using its name.

%#function LinearModel

[Sujit Tripathy]

Thanks, Walter and Steven.