Let me start by saying that I have decided to take a holiday this weekend… for me and my American readers, this is Thanksgiving weekend. I have decided that

**there will be no technical post on this coming Monday, November 29.**

While I expect to be doing mathematics this weekend… it is, after all, my idea of fun… I will treat myself to not having to turn some mathematics into a post this weekend.

I’ve spent some time since last Saturday’s post looking through other data sets available on the Internet. So far, I have found nothing as good as Ramanathan’s data, at least for illustrating stepwise regression and backward selection. While I hesitate to use a third data set from his website, I really haven’t found anything else as good, for what I want to demonstrate.

As for other mathematics… I’ve been nibbling at the edges of aircraft control, abstract algebra, the Kalman filter, and computer performance modeling. Nibbling, I say… getting somewhere, I’m sure… but I haven’t passed any milestones.

So let me tell a story… about final exams, and the stellar interior equations.

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