NPCT

When working on document in LaTeX that is going to wind up as a PDF (e.g. my thesis), I prefer to look at it in Adobe Reader. Acroread seems to give the best impression of what the document will actually look like. In practice, though, I use xpdf, because it has a “reload” [...]

Computer scientists and mathematicians like the movie Sneakers not only because it is about cryptography, but also because the jargon about factoring used in the movie is authentic. The reason it is authentic is because the directory brought Leonard Adleman (the “A” in “RSA”) in to help them. He’s written up some memories [...]

I learned a new Latex trick today. Sometimes you have math notation inline with text, like when you use $…$. Sometimes with long equations, however, you get line breaks. Like if you have $a+b+c+d+e$, it might happily break it into $a+b+c$ and $+d+e$ on the next line. This is ugly, but [...]

I’ve written some fairly heavy Markov chain Monte Carlo code in Java and would like to let it run for a while. The cluster in the Inference Group is not terribly up-to-date and it’s obnoxious to run computationally-significant jobs on colleagues’ desktops anyway. This seemed like a good opportunity to try out Amazone [...]

I am a huge fan of Tom Minka’s Lightspeed Toolbox for MATLAB. I am so dependent on it that I can’t even remember which functions are native to MATLAB and which are Tom’s inventions. However, Tom is at Microsoft Research Cambridge and so he doesn’t spend much time making sure that it works [...]

I am writing a paper on nonparametric Bayesian density modeling and I would like to compare my technique to the standard approach of the infinite mixture of Gaussians (iMoG). You can read Carl Rasmussen’s paper to get a feel for what it’s all about. My plan is to look at hold-out log probabilities [...]

Our downstairs neighbors, who are our very very good friends are moving away. They’re huge karaoke addicts and so we got them a fun parting gift: Rock Band for the PS2. This game is so much fun, it’s painful. Obviously, I know people have liked it, and Guitar Hero has been a [...]

I have this fairly nice setup for my home office, since I work from home more or less exclusively. I like to play the occasional PC game, so I have a reasonable video card setup. I had two eVGA 7600GT video cards in an SLI configuration. Well, this all turned sour last [...]

While I’m complaining about Erlang: why doesn’t Google ever return any hits on the documentation? If I google “perl sprintf” the first hit is the documentation page http://perldoc.perl.org/functions/sprintf.html. The same thing happens if I Google “python array” or “lisp map” or “php echo.” If I type “erlang supervisor” I don’t get anything [...]

Like just about everything to do with Erlang, database driver support appears to be in total disarray. I’d like to be able to store data in a PostgreSQL database and access it reasonably well. Options appear to be

Erlang psql driver that is a fork or something of the code by Erlang Consulting. [...]

In my previous post, I complained a lot about trying to get XML stream parsing working. Ultimately, I just decided to rip the guts out of ejabberd, rather than reinvent the wheel. The relevant files are xml_stream.erl, xml.erl, and expat_erl.c. You can see how to use it in ejabberd_receiver.erl. Frankly, these [...]

There’s a lively debate out there about how one should communicate with clients in a game, in particular UDP vs TCP. I won’t go into details about it, but you can read a lively debate here. The choice for my ridiculous game is TCP+UDP. I want to use TCP for various communications [...]

If you are writing code that is dominated by evaluation of the exponential function, you cannot do without these two papers:

Nicol N. Schraudolph. A Fast, Compact Approximation of the Exponential Function. Neural Computation, 11(4):853–862, 1999.

G. C. Cawley. On a fast compact approximation of the exponental function. Neural Computation, 12(9):2009-20012, 2000.

The implementations described yield 3x [...]

I use Latex Beamer to do all my talk slides. Problematically, however, it can be tempting to pack the slides full of equations. Obviously if you’re presenting mathematical results this is unavoidable. This page on using arrows in equations with Beamer is fantastic. I’m definitely using them in my next presentation.

I’ve posted twice now about starting an Erlang project (one and two). I now have a directory structure and a Makefile that I’m happy with, plus some odds-and-ends from my first attempt at stubbing out an OTP application. I’m now going to begin again, with a healthy dose of Chapter 18 from Joe [...]

Continuing on with the previous Erlang post, there have been a couple of developments: 1) Programming Erlang arrived from Amazon, 2) trapexit.org came back online, and 3) I found this awesome blog.
To remind you of my immediate goal: I want to figure out how to organize a large-scale Erlang project. I want to learn [...]

Per my previous post, I’m going to start a little Erlang project. I’ll call it “North Zulch,” or “NZ” in reference to the tiny little place where the family ranch is located.
There are three things that I’ve had to solve over and over (or at least cut and paste over and over), in [...]

I have decided for some reason that it would be fun to play with massively scalable systems. In particular, I thought it would be a hilarious waste of time to work on an MMO engine. I’m not sure why this seems like a good idea, given that I have more than enough on [...]

We got our Wii primarily as a party-game machine. I certainly enjoy my games, but tend to prefer the PC. We figured the Wii would be fun for when we’re hanging out with friends and family. This has certainly been the case, and we’ve enjoyed hours of Wii Sports at Thanksgiving and [...]

It’s stuff like this that makes computer science research fun.