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Arcanius Upgrades

I’m having trouble sleeping, and the server behind some of the websites I administer went down a few days ago, so I’ve been on an upgrade tear. I just moved this blog from the industrious-but-odd win7/vmware/ubuntu hybrid minimus to a amazon micro instance (free for a year!), presumably virtualized under something like Xen.

All the sites that I’ve moved to this EC2 instance are noticably faster, and Checksum Arcanius is no exception: page generation times seem to be about 10x faster (based on WordPress’s self-reported times at the bottom of the page), and the page load just feels much faster overall.

This is my first foray back into AWS since I played around with it during my Amazon internship in 2008. The experience has been incredibly positive. Amazon deserves tons of credit for what they’ve done with AWS.

On Giving and Interpretting

How closely do you listen to the news?

Today while driving home from a holiday party, I was listening to NPR’s Marketplace Money by KQED. One of the pieces was talking about how lower income people are more giving than higher income people. My immediate question was, “by what measure?” Fortunately, the commentator was good enough to share that information — lower income people are more giving when measured as a percentage of their disposable income given away.

Well, that certainly adds some texture, I thought. I found this graphic (in this article) which shows a similar trend (this graphic is before tax income though, so the numbers are skewed a little more towards the poor):

Giving by income quintiles

What I personally notice about this is that each quintile actually gives more as a total amount than the previous quintile.

Avg Income Giving % Giving Amt Moving sum % Of moving sum % of total
 $10,531.00 4.3% $452.83 $452.83 100% 6%
$27,674.00 2.5% $691.85 $1,144.68 60% 10%
$46,213.00 2.7% $1,247.75 $2,392.43 52% 17%
 $73,460.00 2.0% $1,469.20 $3,861.63 38% 20%
$158,888.00 2.1% $3,336.65 $7,198.28 46% 46%

Indeed, another way to talk about this same data is that high earners (top 20% of income) give nearly half of all money donated each year, which sounds a lot different but is a true statement about the same data.

However, the NPR piece didn’t stop there. They next talked about a study where participants were given $10 and the opportunity to give away any amount of the $10 to another, anonymous, participant. I was npt able to quickly find supporting documents, but the claim was that lower income people gave away an average of $7, keeping $3 for themselves, while higher income people gave away an average of $3, keeping $7 for themselves. The interpretation again was that poor people are more generous and more likely to donate money than rich people.

Again, I thought about it a little differently. This effect shown is correlation and not causation, so the given interpretation is an example of the most classic mistake of statistics. Perhaps, I wonder, are people who are less giving naturally more likely to have high incomes? In other words, does causation go the other way? How would this hypothesis even be tested? And what are the confounding factors?

I try to listen to the news carefully and question everything I hear. In addition to the news just being wrong — in several cases where I’ve known more than what’s presented in a newstory, I’ve seen large omissions and fabrications — there are always alternate explanations and interpretations than the one assumed by the presentation. Despite trying, I still often find myself believing, on a whole, the news as presented by the media I consume.

Skyfall

Much like The Hobbit, the best part about the latest Bond movie, Skyfall, was a song — Adele’s title piece. Unlike The Hobbit, however, Skyfall was actually worth watching in it’s own right. Still, the best part is free:

The Hobbit & High Frame Rate

Today I went to the Metreon 16 Cinemas in Downtown San Francisco to watch the Hobbit with my CSE buddy Jonathan and another friend of his. We selected a show that boasted enhanced sound, a larger screen, high frame rate, and of course 3D.

First off, the movie was pretty bad. I would not recommend watching this for the movie itself. It dragged on with superfluous content that didn’t advance the stories or characters and seemed primarily designed to justify turning the book into three movies. The best part of the movie,  by far, you can see without even going the the theater — it was released as a trailer, below:

Save yourself the money and just watch that a few times unless you’re really interested in the latest movie technology.

Despite being a failure as a compelling telling of a story, the movie was a success in one way: it was a technological tour de force. What intrigued me the most about the billing was the high frame rate (HFR), a doubling of the normal 24 frames per second of traditional cinema to 48 frames per second. I was watching for it and the result is very good: the many big camera pans over lush landscapes appeared much smoother and much nicer visually. I’ve always been distracted by the jerkiness of 24 frame per second movies during panning. I hope this or an even higher frame rate becomes the new norm.

Again, the technology really shined in the sound arena as well. Apart from being considerably too loud — which I blame the theater for, not the movie — the sound system was still the best I’ve encountered. At one point, in a cave full of snoring dwarves, we all thought we heard someone directly to our right start snoring (Jonathan even turned to see if it was me!). Alas, it was just a better-than-average sound localization. Listening more carefully, I definitely could localize sounds to specific places in the theater much better than I recall being possible normally.

The 3D with the circularly polarized glasses was excellent as usual.

Too bad the movie sucked.

Theoretical Chemistry

Christine Isborn is a theoretical chemist that I recently worked with to create a web site. I think it came out pretty well. Go check it out!

Full disclosure: Christine is my girlfriend!

Auto-Updating GNU Screen Window Names

It took a bunch of searching a testing, but I got something that works for me and I like well. Instead of every screen window being called “bash” or being named manually, I now have them all named after the working directory. This is the magic:

PROMPT_COMMAND='echo -ne "\033k$(basename $PWD)\033\\"'

PROMPT_COMMAND gets run every time bash displays a prompt, and those particular escape characters do the magic.

To avoid crap outside of screen, I did this:

case ${TERM} in
screen)
export PROMPT_COMMAND='echo -ne "\033k$(basename $PWD)\033\\"'
;;
esac

Which is more general than it needs to be, but maybe I’ll expand it in the future.

Emissions

My car just failed an emissions check. I have an offer on the table to sell it for $2000 and walk away.

When I bought it two years ago, the purchase price and other “miscellaneous” items came to $3300 and I have spent about $2000 in repair and maintenance (including nice new tires) over that time. I have also spent $3600 on gas in that same period.

The monthly operating expenses are $150/month for gas and $80/month for maintenance, so about $240/month give or take. If I sell it, the capital outlay would have been $1300, or about $650/year or 50/month, which is equivalent to a nice low car payment.

If I don’t sell it and can keep it passing emissions tests, I’m sure I could drive the car for another 8 years at which point it will be worth nothing, so capex becomes $330/year or $25/month, basically negligible. I’d expect the repair bills to average lower if I’m not replacing tires all the time, but to remain about the same if emissions continue to give me trouble and are repairable.

Decision time: sell the car now or try to get it to pass the smog? I’m pretty happy with the car otherwise, and I have one free retest I can do before I have to make a final decision.

My goals in rough order of priority are:
1/ maximize convenience
2/ minimize cost
3/ screw the system

I’m thinking about buying some of this stuff and driving around a bunch tonight and going for the re-test tomorrow. If I still fail, I sell the thing to the dude tomorrow. If I pass, I have another two years before I have to make the decision again.

Better ideas?