estimating second derivative in python

[pouya-rabiei]

Dear Cartool community

I am Pouya Rabiei and am analyzing EEG microstate using MNE, and sth like MetaCreation is not defined.
I am trying to estimate it myself based on the quality metrics that are applicable in Python or MNE.

I was wondering how Cartool calculates the second derivative? Is there a formula I can access?

Best regards,
Pouya