UndefinedFunction error for a known script

I'm running a lab exercise on topic real-time calculation, which runs a simple pump, from my laptop. It runs ok for an hour and then all of a sudden I get the following error:

The 'real_time' function/script is known. It's basically a script triggered by timer that calculates heat and mass balance only, no external functions used. The error is pointing to:

I asked the teacher assistant and he found it strange, basically did not know the answer. Any idea what could be the problem and how to fix it? Thank you!

[Angelo Yeo]

What does MATLAB result in with the following command?

>> which real_time -all

[Walter Roberson]

Does your code contain any cd() calls?

[fani]

Thank you for asking. I have checked it and it does not contain any cd() or 'change directory' function call.

Answer 1

[Shivam Lahoti]

Hi Fani,

I understand you are receiving a 'MATLAB:UndefinedFunction' exception. The error states 'undefined function or variable 'real_time''.

This can stem from multiple reasons, and one of them could be missing dependencies. Your MATLAB setup might be missing a toolbox add-on, or 'real_time' might be a function from some File Exchange submission that was not properly downloaded to your system.

To verify if the 'real_time' function is a MATLAB built-in function and if you are missing the toolbox that contains the function, run the following in the MATLAB CLI:

help real_time

If the above command shows that this is not a MATLAB built-in function, it might be the reason you are receiving this exception. Kindly check that the function file is present and is in the MATLAB path.

I hope this helps.