WPF Parallelization fails

[sezelt]

There have been reports of the mpire distributed WPF optimization failing with errors like

AttributeError: Can't pickle local object 'WholePatternFit._fit_distributed.<locals>.f

This appears to only affect Windows systems.

I think the fix is to enable dill serialization:

py4DSTEM/py4DSTEM/process/wholepatternfit/wpf.py

Lines 748 to 753 in 1137637

	with WorkerPool(
	n_jobs=num_jobs,
	shared_objects=fit_opts,
	) as pool:
	results = pool.map(

should be modified to become:

        with WorkerPool(
            n_jobs=num_jobs,
            shared_objects=fit_opts,
            use_dill=True,
        ) as pool:

mpire produces threads differently on Windows vs UNIX and so there can be serialization errors that only show up one one platform when transmitting complicated objects to threads. Unfortunately I do not have a Windows machine to test this on at the moment, so someone else will have to try this and let us know.