It probably got missed in the who conjugate gradient mess, but I think the main point of the post was that instead of using one giant for loop that contains you

It probably got missed in the who conjugate gradient mess, but I think the main point of the post was that instead of using one giant for loop that contains your logic, logging, stopping conditions, etc., you can seperate out your for loop into different parts so that you can mix, match, and reuse your logic code, loggging code, stopping conditions code, etc.