NAN value in FA.csv

I use AFQ to track fiber bundles. In the generated FA files, some whole fiber bundles are Nan, and some sections are Nan. I would like to ask that this is a problem of tools and the original data I collected. How to solve this problem?

Thank you.

[avantika9]

@xk005 I was wondering if you were able to troubleshoot this issue. I have the same problem.