When I ran the preprocess.py, I would get this error: IndexError: cannot do a non-empty take from an empty axes.

Traceback (most recent call last):
File "preprocess.py", line 54, in
main(preprocessor, args.data_path, args.output_path)
File "preprocess.py", line 39, in main
datas = preprocessor.build_from_path(data_dir, out_dir)
File "/media/fish-bsp/fish_4TB/Audio/StyleSpeech-main/preprocessors/libritts.py", line 132, in build_from_path
f0 = remove_outlier(f0)

I think the problem is from here:

How can I revise the code to let it run successfully? Thanks.