Monday 21 March. One edit; as usual, search on “edit”.
First, something of a time-sensitive nature.
While I was channel surfing last night – since “Blue Bloods” wasn’t on – I discovered something interesting. Tonight is a full moon… but not just any full moon. The moon will be at its closest approach (pick one: periapse, perilune, periselene, pericynthion).
As the second of the following two links put it, there’s a full moon every month and the moon goes through periapse every month – but they don’t often happen at the same time.
Here are a couple of links… more things will undoubtedly appear on the Internet as this day goes on.
I’ve got another book on order… differential geometry this time, rather than multicollinearity. What the heck? It’s less than $35 – and my history, especially the recent purchase of a completely unknown “book” that turned out to be a small collection of printed and bound Wikipedia articles – suggests that I will spend $35 on a book sight unseen. But this wasn’t a random book chosen for its title.
This one was recommended by Eberhard Zeigler in one of his two volumes on “applied functional analysis”. I like his style… I also own the first two volumes – so far the only volumes – of his “quantum field theory”… I have refrained from buying his seven (?) volume set on nonlinear functional analysis. Let me get through the two regular functional analysis books first. (In case you’re wondering, functional analysis could be called the study of infinite dimensional vector spaces… and those are typically spaces of functions.)
Anyway, what I’ve ordered is “Modern Differential Geometry for Physicists” by C. J. Isham. As I said, I like Zeigler’s style, and this is the only introductory book he recommended for non-mathematicians. I have to look at it. (Sadly, while math books tell me what, physics books tell me why. Math books all too often focus on individual trees, physics books talk about the forest. Part of the problem, of course, is my own mathematical limitations.)
And now to business.
If you’ve been following this blog for a while… because last Monday’s post was not about the current topic – multicollinearity – you might have guessed that something interesting happened while I was doing calculations for the post (which will now appear in two parts, so that the interesting result is by itself).
I was surprised – very surprised – by the results of the calculation. If you are curious and impatient, try investigating the multicollinearity of the centered Hald data. (Edit: Oops. Actually, it was the standardized data that shocked me.) (That is, just subtract the column mean from all the observations in a column.) Or you can wait for me to do it… I assure you, I will.
Instead, I put out one of my three not-quite-ready reserve posts. I am a little torn. Should I go ahead and put out the second draw poker post? Or should I save it for a rainy day? As it is, I should probably write a third post. The first one was the probability of hands being dealt… the second will be the probability of improving a hand – assuming you have at least a pair already… a third post could investigate what to do when you are dealt nothing, not even a measly pair. (After all, we showed that that happens half the time.)
The next multi-collinearity post looks quite straightforward – famous last words! It finishes off multi-collinearity in the standardized Hald data. Maybe I should put it out.
I haven’t decided. After all, whichever post doesn’t go out becomes one in reserve. (Reserve posts don’t have to be on different topics – they just need to be nearly ready for the mechanics of publishing, so that I can bail on one at 2 in the afternoon and still get a different post out.)
Finally, the blog set a record on Monday… 309 hits in one day, which shattered the previous record of 258 set more than a year ago, back in February 2010. The blog also crossed a milestone on Monday: more than 100,000 hits since its inception.
Oh, I just checked one other statistic. Sometime recently the blog crossed another milestone: more than 15,000 spam caught since its inception. It almost certainly happened this week.