Posted in programming, science, wikipedia at 11:50 pm by danvk

While reading Wikipedia’s Mandelbrot set article, I stumbled upon the exceedingly cool Buddhabrot, and the even cooler Nebulabrot:


I’ll write more about the math later, but what I find most interesting about it is how it naturally fills in the “boring space” inside the Mandelbrot set:


The interior of the Nebulabrot is also a fractal, as a zoom shows:


Those little buds are all Mandelbrots.

Being a CS-type, once I saw the definition, I immediately set out to render the most detailed Nebulabrot ever seen. It’s 10240×7680 and gorgeous. Here are some zooms (click for full-res versions):


The most “nebular” part


“Island universes” along the negative x-axis

Here’s a link to the full JPEG (4.3MB) and the full PNG (44 MB).

If you zoom all the way in, you’ll see some graininess, even in the PNG. This isn’t a compression artifact. It’s a hint of further structure. If I’d cranked up the dwell limit in my rendering, the noise would have been even more miniature Mandelbrot sets!

Update: MarkCC over at Good Math, Bad Math has a post about MapReduce that discusses the way I generated this at length.


NCAA Tourney 2007

Posted in sports, web, wikipedia at 9:04 pm by danvk

A few weeks ago, I looked at the Wikipedia edits to the 2006 NCAA Tournament article. Here’s the edits chart for this year’s tourney, as promised.


For comparison, here’s the chart for last year:


The overall features are quite similar: the important dates stand out clearly in each chart. The total edit volume in 2007 is about double what it was in 2006, which is consistent with Wikipedia’s rapid growth. The edits were more front-loaded in 2007. Selection Sunday was far and away the busiest day, and the edits decreased steadily into the later rounds. This may indicate that fans contributed content relating to their favorite teams, and then stopped once that team was eliminated.

Shortly before last year’s tournament, I wrote a program to create a basic article for every NCAA tournament, from 1939-2005. The articles had a list of teams, locations, and a bracket. The idea was that, once the tournament got underway, other contributors would spruce the articles up a bit with some individualized content. Here’s a plot of the cumulative edits to the 1939-2005 tourney articles.


There are clear spikes during March Madness each season. Cumulative, there have been 1,493 edits to these articles by users other than myself, an average of 22/article. This is a bit skewed by the more recent tourneys, though. The median number of non-Dan edits is 10/article, which still isn’t bad. Wikipedia has its own flavor of the “release early and often” mantra from open source software. It’s not important that the article be perfect the first time around. It’s more important to just put something out there so that others can improve upon it.


NCAA tourney

Posted in sports, tv, web, wikipedia at 11:26 pm by danvk

I’ve been enjoying March Madness the past few weeks, even though my team got knocked out in the first round.

Internet video really is coming into its own. This year, for the first time, you can watch the games online with March Madness on Demand. As with the NewsHour Online Video Archive, there are still some kinks to work out. Biggest gripe: it only works in Internet Explorer 6 on Windows. No love for Mac users like myself. What’s worse is that you don’t even get a message telling you that IE6 is required if you load it in Firefox. It just mysteriously doesn’t work. Hopefully this tool will be better next year. The main thing is that it exists at all.

Oh, and if a game is being broadcast on CBS in your area, you’ll get a message saying it’s been blacked out. Yeesh.

The Wikipedia article on the 2007 tourney has been fun to watch. In the last ten days, it’s received over a thousand edits. Wikipedia edit counts aren’t a bad way to track current events. Here’s what the edit history for last year’s tourney looks like:


The major events stand out in stark relief. One caveat: if an article gets protected by an administrator in response to vandalism, it throws a wrench into the fluidity of edits. I’ll post a similar chart for this year’s tourney after it’s over.


Wikipedia Signpost RSS Feed

Posted in wikipedia at 11:26 pm by danvk

Unbeknownst to most of its readers, Wikipedia has its own weekly newspaper, the Wikipedia Signpost. It covers stories in the press about Wikipedia, internal controversies, and technical changes to Wikipedia.

The Signpost was sorely lacking an RSS feed, so I’ve put one together at http://feeds.feedburner.com/WikipediaSignpost. The feed should get updated weekly with the Signpost, with only an hour or two delay from publication.

I set this up as a simple Ruby script, but in retrospect, had I been more ambitious, I would have used Plagger or Dapper.

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