The error you're encountering (Undefined function handleparams for input arguments of type double) means that the MATLAB function handleparams.mis not available to the parallel workers when your code runs.
This usually happens in parallel computing because the workers run in their own space and don't automatically have access to all your local files. So, if your code uses a custom function like handleparams, you need to manually send that file to the workers.
To fix it, you can use this command before executing your parallel job:
addAttachedFiles(gcp, {'handleparams.m'});
This tells MATLAB to send the file to all the workers. Just make sure the file handleparams.m is in your current folder or somewhere on the MATLAB path.
Feel free to go through the following documentation:
Parallel Pool File Attachments:
gcp:
