07.15.07

Dan fights Bad Math!

Posted in math at 11:07 pm by danvk

Inspired by the recent Laffer curve fuss, I’ll be doing my MarkCC imitation tonight, calling out the scourge of bad math wherever it rears its ugly head.

Case number 1: I’m on something of an Alex Haley kick, so I’ve been reading The Autobiography of Malcolm X. Here’s a passage that jumped out at me:

Here is an example: a British anthropologist named Dr. Louis S. B. Leakey is displaying some fossil bones—a foot, part of a hand, some jaws, and skull fragments. On the basis of these, Dr. Leakey has said it’s time to rewrite completely the history of man’s origin.
This species of man lived 1,818,036 years before Christ. And these bones were found in Tanganyika. In the Black Continent.¹

How good of Dr. Leakey to be so precise! And here I thought radio-carbon dating was only accurate to about one part in a hundred at best. What year was this written in again? 1964? Well, 1,818,036 + 1,964 = 1,820,000. Something makes me think Alex never learned about significant figures..

Case number 2: This one’s an exercise for the reader, since my tongue is tied. According to The Economist’s Technology Quarterly,

The average installed storage capacity of a Fortune 1000 company grew from 198 terabytes in early 2005 to 680 terabytes in October 2006, according to figures from Deloitte, a consultancy.²

What was different about the Fortune 1000 in early 2005 and October 2006? Why might this claim by incredibly misleading?

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07.08.07

At the Beach

Posted in personal at 1:01 pm by danvk

From left to right that’s my nephews James and Michael, my niece Katie, and me. Good to see that Michael’s copying my look.

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07.07.07

The Token Wimbledon Post

Posted in sports, tennis at 12:46 am by danvk

I took some grief for writing too much about the French Open, so I’ve avoided saying anything about the last two weeks at Wimbledon. I get one post though, right?

The main story has been rain. It’s been so wet that Nadal wound up needing five days to finish his third-round match against Robin Soderling. The tournament got way behind schedule, so many players have been playing on back to back to back days. Men’s quarters were today, men’s semis are tomorrow, and the finals are the next day.

That makes for some really tired players, so we’ve been getting a few surprise results. A lot of matches have been one-sided at the beginning, then a player gets tired or hurt, and the match suddenly reverses. That’s what happened to Andy Roddick today. He was up two sets and a break on Richard Gasquet, but wound up losing a 6-4, 6-4, 7-6, 7-6, 8-6 marathon. NBC must be all kinds of pissed. Instead of getting a marquee matchup with an American, Andy Roddick vs. Roger Federer, they get a lopsided matchup with a player nobody’s heard of. Remember the tight schedules? After playing a four hour slugfest than finished after 8 PM, Gasquet has to wake up tomorrow morning and play Roger Federer at noon. It’s going to be a blowout.

The women’s final is also going to be a blowout. Venus Williams has been playing out of her mind, and Marion Bartoli (who upset Justine Henin today) has never played in a Grand Slam final before. There’s a fine tradition of choking in your Grand Slam final debut on the women’s tour. See Anna Ivanovic and Justine herself for reference. Expect more of that tomorrow.

The one interesting match is the Nadal vs. Djokovic semi. These guys will both be exhausted. They’ve both played several days in a row and had a few five-setters. I’m picking Nadal in five, but I’ll be rooting for Djokovic.

Another random note: Bud Collins, the veteran NBC tennis commentator, is retiring. Good riddance. This guy is like the Dick Vitale of tennis. Nobody likes him. His role now is mostly to do cringe-inducing post-match interviews with the champions. A sampler: Bud: “On clay, Rafa is el Rey!” Nadal: “hehehe, ahhmm” (awkwardly looks for anyone else to talk to). Way to go, Bud.

Update: An update doesn’t break my one-post limit, does it? I called all three matches correctly. Venus and Fed rolled, and Nadal won. I called five sets, but it only went three. Djokovic hurt his foot and had to retire in the third set, tied at one set apiece, presumably on its way to a thrilling fifth. =) I’m picking Fed in four tomorrow. The final is on NBC at 9 AM EST/6 AM PST.

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07.05.07

“The Cathedral and the Bazaar”

Posted in books, programming, reviews, wikipedia at 10:08 pm by danvk

There’s a long tradition of great titles in the software engineering world. Djikstra’s “Goto Considered Harmful” has spawned thousands of imitators, and even a meta-paper. Fred Brook’s The Mythical Man-Month clicks as soon as you understand the title. Eric S. Raymond’s “The Cathedral and the Bazaar” gives open source software its defining image.

I read “The Cathedral and the Bazaar” as an introduction to the world of open source software for someone interested in joining it. There’s a history lesson to explain where you’ve come from and what you’ve accomplished. There’s arguments and a case study to show that you’re on the right ship. And finally, the essay serves as a call to arms, to get you excited about becoming a contributor.

I found the history lesson most interesting. I’d had some understanding of this before, but lacked much detail. ESR gives a first-person account of UNIX and software development from the late 1970′s to the present. This is the canonical story of open source. It has its heroes and villains, its true believers and false idols. There’s the Moses figure, Richard Stallman, who freed the users of UNIX from the oppressive yoke of restrictive licenses. But like Moses, he couldn’t enter the promise land. Open source stagnated, awaiting its Last True Prophet. This was Linus Torvalds, who created the Linux kernel, the last piece of the open source operating system.

ESR really uses that of tone. I get the sense that he’s intimidated by Richard Stallman and absolutely idolizes Linus Torvalds. The essay drips with hero worship. Linus is the visionary whose vision he’s writing about.

Beyond the hero worship, there is a clear exposition of the open source model. In order to avoid the problem of N^2 channels of communication amongst N contributors, open-source project have a small set of core developers. These core developers have total control over the project. They decide what gets checked in, and where the project goes. It’s a (hopefully) benevolent oligarchy. Outside of that core, there are occasional contributors and legions of testers, who can submit bug reports. Does this strict hierarchy really sound like a Bazaar?

If you want a real Bazaar, think about Wikipedia. Since I’ve never contributed to an open source project, I kept it in mind as a reference point. It works pretty well, but this perspective has the side effect of making open source development look positively Cathedral-like. Think about it. Rather than having a core set of contributors and legions of users/testers, Wikipedia explicitly aims to make all of its users into contributors. It does this by lowering the barriers to entry as low as it conceivably can, even if this leads to vandalism. All that’s needed to contribute is the ability to write in some language. Last time I checked, English had a few more speakers than C++. Rather than just reporting problems, users are empowered to fix them on the spot. See a typo? Just correct it. Want a citation? Find one and plop it in to help future readers.

I enjoyed “The Cathedral and the Bazaar” for the history lesson, but I find its central image misleading. The development process of open-source projects is as well-organized as any commercial venture.

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