What is the math behind the reputation score?

I read few articles on - 1) what is reputation score and 2) how the score can be converted.
Link 1

Link 2

However, I don't see how the score changes on every vote and comment. Could anyone enlighten me with the math behind the score calculation? I am trying to calculate reputation from user's activity history.

@shenanigator
@digitalnotvir
@sevinwilson