In-N-Out

So I finally, after 29 years of existence, got a chance to eat at the much-hyped In-N-Out Burger chain, and I have to say, I was pretty disappointed. People in California talk about this place as if Jesus himself returned to Earth and started a burger chain. This view seems to be corroborated by the quotes on some of the utensils. It just didn't do it for me, though. I got the same kind of greasy burger you can get at any fast food joint, and In-N-Out has an extremely limited set of ingredients (no bacon, no mushrooms, and no cheese except American).

My guess is that some of the hype originates from the existence of secret menu items, which lets select patrons feel as though they belong to an exclusive club of people who know the code name for each subset of the 5 ingredients In-N-Out carries. It's the same phenomenon as knowing the correct grammar for constructing Starbucks drink names. (I'm pretty sure it's a regular grammar.) Anyway, I'd be much more likely to go back to In-N-Out if someone tells me the secret word for "not drowning in grease".

keeping myself organized

I'm supposed to be working on my ECCV paper right now, but I decided to procrastinate by streamlining my eLife. It's pretty surprising how many cool Web 2.0 tools there are for keeping yourself organized. With each new tool I discovered, I would usually think "great, now if only I could also x", and almost every time, with a little bit of searching, I managed to find another tool that accomplishes exactly x.

Here are some things that absolutely everyone should do:

1. Use an RSS reader. Hopefully you already do this. You should not be checking and re-checking dozens of sites for updates. I use Google Reader, but there are plenty of others. There are some slightly less obvious uses of RSS too. For instance, if you find yourself repeatedly searching Craigslist for something, you can subscribe to the search as an RSS feed instead.
   
2. Do not subscribe directly to RSS feeds that have hundreds of items each week (Digg, TechCrunch, etc.). This, as they say, is like drinking from a firehose. If you are checking these sites for articles on a particular topic, use FeedRinse to filter the RSS feeds using keywords. Otherwise, use AideRSS to filter out the less important items from each feed. AideRSS appears to use a ranking algorithm similar to Google's PageRank to measure quality.
   
3. Use some kind of calendar application. I recommend an online one like Google Calendar, as I use different computers in different locations. With Google Calendar, you can add events by entering text like "meet with Xander at 3 PM on Tuesday" into a field, and this event will be added to your calendar, even if you don't know anyone named Xander. Even nicer is that several sites, like TripIt, communicate directly with your Google Calendar, so you can keep all of your scheduled events in one place without even entering many of them manually.
   
4. Collect data on yourself. You need to know how you are spending your time and money. RescueTime is pretty good for the former, and Mint is good for the latter. Both of these require virtually zero data entry on your part. Actually, here's a tool I would like but was unable to find: something that punishes you for wasting time or money, or rewards you for being good. The website stickK is sort of close to this, but requires too much manual effort.

And because no such tool exists, I am writing this blog entry instead of my ECCV paper. Oh well, at least I'm producing something instead of consuming, even if it is of little value.

MySong

MySong, a project I worked on last summer with Dan Morris and Sumit Basu of Microsoft Research, seems to be hitting the blogs:

http://www.boingboing.net/2008/03/03/microsoft-researchs.html

I'm a bit surprised at the negativity of some of the commenters. Remember: this isn't supposed to be the ultimate solution to music composition. The chord progression model is pretty simple and the synthesis (at least without Band-in-a-Box) is just a Let It Be pattern. What MySong does do, however, is let people who have no idea how music "works" play with basic composition. I know a fair amount of music theory and still had tons of fun singing into MySong and messing with the chords that came out. In fact, I spent more time doing that than actually working on the code (but don't tell anyone that).

medoids

Suppose I have a set of points. The mean of this set of points is the point (not necessarily in the set) which minimizes the sum of its squared distances to all the points in the set. A related concept is the medoid, which is like the mean but is restricted to being one of the points in the set.

Interesting fact: the sum of squared distances from the medoid to all points in the set cannot be more than twice the sum of squared distances from the mean to all points in the set.

This imples that for the k-medoids problem, if you have an algorithm that achieves some constant times the optimal solution cost, this same algorithm also achieves a constant factor approximation for the k-means problem.

Again, this is probably trivial if you're a theory person, but I think it's fun.

double triangle inequality

The triangle inequality is one of the properties of a distance metric d. It states that, for any x, y, and z:

d(x,y) + d(y,z) ≥ d(x,z)

A somewhat lesser-known (but easy to derive) extension of this is the double triangle inequality for squared distances:

2(d²(x,y) + d²(y,z)) ≥ d²(x,z)

I have never seen the double triangle inequality used for anything. However, I would think it would be useful, given the prevalence of squared distances in objective functions. The k-means objective, for instance, is to minimize a sum of squared distances. For problems in which the objective function involves non-squared distances, the ordinary triangle inequality is often used to prove bounds on an algorithm's performance. I'm not sure why I haven't seen similar things with the double triangle inequality and squared distances.

Also, I should point out that I'm not really a theory person, so my not having seen something provides very little evidence for the nonexistence of said thing.