> ChrisAcheson.net_

Archive for April, 2009

Debian and Back Again

Tuesday, April 28th, 2009

I decided a few days ago that Xubuntu was just too sluggish on my old, ailing laptop. I’d heard that Crunchbang was a bit faster, so I tried it out, but X just segfaulted on startup.  The same thing had happened on Xubuntu 8.10, so I’d been sticking with 8.04.  I tried Arch next, hoping that something not based on Ubuntu would fare better.

Arch seems like a neat distro, but it didn’t solve my problem with X. After much digging (including a couple sessions with gdb), I found out that the newly-rewritten PCI access code in Xorg 7.4 was trying to initialize my laptop’s broken PCMCIA hardware, causing the segfault. Someone on the #xorg-devel IRC channel also pointed out a patch that fixes the problem.  The patch did fix the segfault, but after all that fucking around, I still couldn’t get X to actually start.  Even with the basic VGA driver, it would immediately drop me back to the command line without giving any errors at all.

Yesterday, I finally gave up and decided that Arch was too bleeding-edge for my poor broken laptop.  I ended up going back to Debian, the first Linux distro that I ever used. I’d originally stopped using it because the “stable” version was too conservative (and the “unstable” and “testing” versions too prone to breakage), but in this case that seems like a good thing.

In order to keep the machine running at a decent speed, I’m just using a basic window manager in X instead of a full desktop environment.  I’m giving xmonad a try right now.  I think I’d need a higher-resolution screen to really take advantage of the “tiling window manager” concept, but I do like how it’s almost exclusively keyboard-controlled, and how it lacks space-wasting window decorations.  I’m also trying the Vimperator plugin in Firefox (or rather, Iceweasel), allowing me to cut down significantly on my mouse usage.

I still need to delve into xmonad’s configuration, set up the status bar, find a decent xterm replacement, and install ProFont.

Rochester OpenPGP Users Mailing List

Monday, April 20th, 2009

The keysigning party on Saturday went well.  We decided to create a mailing list to keep in touch and discuss ways to promote PGP use locally.  From the list’s description:

This group is for PGP/GnuPG users in Rochester, NY to:

1) Discuss ways of promoting the use of OpenPGP encryption
2) Arrange keysignings in order to expand the local web of trust
3) Get help with using PGP, GnuPG, and related programs

If you’re interested in joining, you can do so here.

Math for Programmers

Wednesday, April 1st, 2009

I bookmarked a blog post called “Math for Programmers” years ago on one of my random “scratch space” wiki pages, and just rediscovered it tonight.  I figured I’d share:

The right way to learn math is breadth-first, not depth-first. You need to survey the space, learn the names of things, figure out what’s what. [...]

I think the best way to start learning math is to spend 15 to 30 minutes a day surfing in Wikipedia. It’s filled with articles about thousands of little branches of mathematics. You start with pretty much any article that seems interesting (e.g. String theory, say, or the Fourier transform, or Tensors, anything that strikes your fancy.) Start reading. If there’s something you don’t understand, click the link and read about it. Do this recursively until you get bored or tired.

My timing on this is interesting.  Over the past few days I’ve started playing a bit of poker (Texas hold ‘em, against computer players in PokerTH), in lieu of my usual habit of compulsively playing quick games of FreeCell at random moments.  For the sheer nerdy fun of it, I want to write a program to calculate the exact odds that I have a better hand than all of my opponents, given the cards that are visible at any particular time (pre-flop, flop, turn, and river).

I’m sure it’s a solvable problem, but I’m having trouble simplifying the staggering number of permutations involved.  For example, assuming you’ve got your two-card hand, there are 1,225 possible hands that a single opponent could have from the remaining 50 cards.  If you have six opponents, there are approximately 9×1017 possible combinations of hands that they could have.  We only care about the best hand among our opponents, so I think we can simplify things by assuming that the math is the same for six opponents as it is for one, except that any given hand is six times more likely to occur.

Anyway, I’m thinking of reading up on combinatorics.  I got a bit from my discrete math and probability & statistics courses in college, but I feel like I’m missing something here.  I’ve always been interested in probability and permutations in games, so it seems like a good subject to pursue.