Blog, by date: 2008_oct

from the desk of travis johnson.

Boom De Yada (from 2008/10/31)

I think I've already told most of my friends about this… but it's just way too awesome to not have documented somewhere. Doubly-pronged awesomeness, actually:

Happy Birthday to Me, Pt. 2 (from 2008/10/28)

Happy Birthday To Me (from 2008/10/26)

I should have written this up sooner, but I guess it worked out well because the last of it didn't happen until just recently.

My friends did a fantastic job of throwing me one hell of a birthday this year. Beals made it up a little bit early to begin the celebrations with food and manly stuff. Then Katie and I had a joint birthday dinner at Boca de Beppos. Tuesday Sharvil and I made it out for a while. Wednesday we had a nice dinner at Shultzy's, though they're kindof in the doghouse for the service that night. Thursday Jackie took me out to Sonrisa, which was absolutely delicious. And finally, Friday night Jackie gathered up a bunch of the Brazil crowd into Finn MacCools, and it was absolutely wonderful to see them all.

Grandma also sent a few bucks my way. I'm still trying to decide what to do with that. The new MacBooks are really flashy and great, and pretty tempting… but I'm a <em>long</em> way off from one of those. There's a chance I could make up the difference by shuffling some stuff around, but my last few attempts to sell stuff on CraigsList have not been all that impressive. NewEgg has a 3.16ghz Core 2 Duo that is very, very tempting… but would require some other upgrades.

But for tonight, and probably tomorrow, it's back to German and trying to not get too distracted by such possibilities.

Smart People Shows (from 2008/10/26)

Sharvil and I started watching Numb3rs today, from the pilot episode. We both basically decided that it's really nice to watch shows that are sortof motivational in a way. Admittedly, they're mostly designed to motivate you to watch more shows… but I think Numb3rs has been an important show for me, if for no reason other than motivating me to keep working on stuff when I'd rather not or when I'm nearly too frustrated to keep going. (I have been watching it for a couple years now, if that wasn't obvious). Anyways, it's usually worth the Numbers Painfully Awkward Lines and just general cheesiness and admittedly odd scenes. (Look up Numb3rs on TheRecapist and prepare to giggle a bit.) And it turns out a fair bit of the math is pretty legit, even if usually the equations he's writing on the boards are sortof generic and not necesarily what he's talking about.

But in any case, it has occurred to me that I really enjoy watching shows about smart people, or the nearest approximation you can get while still being a show. Charlie Epps is maybe the closest to what I aspire to, but Brennan and House in Bones and House MD are both great, brilliant characters. I have to say that the last season finale of Bones was a little sad in this respect, but you'll have to watch it yourself–I won't spoil it! And House goes without saying. Though, I think he 'try the craziest thing you can think of and run with it to see how far it will get us’ works better in math and computing than medicine. At one point I had a list of the top ten episodes of House… I'm not sure I could come up with such a solid list for Numb3rs, but it'd probably be worth a try. Another day, another blog.

Getting an AMATH Minor at the University of Washington (from 2008/10/26)

One of the secret gems at the University of Washington is the minor in applied math option. At least I think it's somewhat secret. Most of the people I tell about it haven't really heard of it. But yeah, here's the deal: You only need to get through calculus and four more classes to get this minor! And a lot of programs require calculus anyways. I've taken most of the undergrad AMATH courses, so I figured I'd write something up about which ones I recommend the most.

This will vary a little bit. Most engineering majors have to take Differential Equations and Linear Algebra. And, most opt to take MATH 307 and 308. I recommend their AMATH equivalents, 351 and 352. I would venture that the AMATH courses will be far more worthwhile in your studies after these, and in most cases they will count towards requirements. I would take AMATH352 whether or not you had already taken another linear algebra course. It covers a lot of ground you just don't usually cover in linear algebra, like defining function spaces and isomorphisms.

If you're just getting started, though, get a feel for what it's like with AMATH 410: Introduction to Computational Biology and Chemistry. The webpage says Prof. Eric Shea-Brown is teaching it next Winter ’09, and he's a great teacher and very helpful. It only requires a knowledge of calculus, but he'll show you lots of interesting stuff. And don't be put off by the relatively high course number, it's so that graduate students from other departments can get some credit for it. Hopefully this sticks around for a while.

If that went well for you, or you want to skip to the big guns, sign up for AMATH 301: Introduction to Scientific Computing. Try, if at all possible, to take this autumn quarter, with the AMATH department chair Nathan Kutz. He'll bend your mind with mathematics, but have you cracking up the whole time. Then you'll think he's trying to kill you with the homework, but he or his TA's will have helpful office hours. This class is truly what sparked my interest in mathematics in general. You'll cover a lot of ground and it will require some effort, but as Nathan says, 'You'll be a MATLAB superstar!’

Now, depending on whether you took linear algebra or differential equations(or perhaps which one you enjoyed more, if you took both and skipped out on something else), sign up for either Discrete or Continuous Mathematical Modeling- MATH381 or AMATH383. The MATH381 class counted as AMATH381 for me, so make sure it'll count if you go that route. Both are pretty interesting.

So, now you should have some idea what you're getting into. Best of luck on your studies!

A few more exotic uses for older hardware (from 2008/10/22)

There are tons of posts on the internet about what to do with older computers. In general, they say some of the same things: Linux/Firewall, Media Server, and 'BitTorrent Box’. (Incidentally, the lattermost somewhat confuses me. I guess people want to download files on a separate machine in case it has viruses or whatever… but if you're using bit torrent so much that it's worth having a separate box for, you're probably still gonna be upset if a virus takes it out. Or you could just use antivirus or an alternative OS. But I digress.) Anyways, for the uses I'll outline here I'm going to assume that you (at least roughly) fit into the prototype of 'I have a pretty decent computer sitting around that never really gets used.’ In my case, I tend to upgrade and want to keep the old one around because it's still a pretty decent computer, but want to use the newer one for bigger and better things. Like reading xkcd and refreshing google news over and over again. Heh.

One thing you might want to look into is SAGE. It's a fascinating compilation of software in the spirit of MapleMathematicaMATLAB/Magma, but with a Python twist and a snazzy cross platform web interface. There is definitely a time for using as many of the fastest computers you can… but honestly in most computational mathematics stuff, you're going to get 1000-1000000 speedups by using the correct algorithms, and maybe a 2x speedup by using a faster computer. So use a good algorithm on your older computer, and implement RSA. Or experiment with 4th order accurate Runge Kutta. Or whatever. Plus it's a totally good excuse to play with Cython, which I've been wanting to do for about six months now. Anyways, it's a handy play to keep all your Project Euler solutions.

Another idea is backups. While most people say something to the effect of 'run samba or DAV’, I'm gonna step it up a notch and say, 'Use git or rsnapshot’ The version control system Git is Linus Torvald's latest project, meant to replace BitKeeper by being a super-cool distributed way to keep track of your source code. It's got a lot of people talking, and there's a lot of discussion of it's relative merits against Mercurial, bazaar, let alone against more conventional things like the Concurrent Version System and Subversion. While a big part of the draw of distributed VCS's are their non-reliance on a central place to store it all, it's nice to have a copy of it somewhere you can get at it, for the time when you need to pull down a copy of your last draft from a library computer or whatever.

To grab some bonus points here, someone wrote a quick Makefile to take ReStructuredText files to nice-looking HTML, which they added to to their git post-commit scripts to push into their webroot. Cool. Here's their page and how they pulled it off.

Rsnapshot is another really sweet idea. They basically wrote an open-source, fast, easy-to-access Time Machine. At it's core, this project just rsyncs stuff from your home directoryroot filesystemSMB sharewhatever to some backup directory on a regular time interval, giving you some number of dailyhourlyweeklymonthly backups of your files. The key improvement here is that they use symlinks instead of full copies, so you actually only have one copy of each version of the file, which drastically reduces the space requirement while still giving you the ability to go back in time. But because it's just filesystem data and symlinks, it's really easy to get around in it without special software.

Incidently, if you're running a 'server’ for any of this stuff, you might as well deck it out with firewalling, squid caching, and media serving. I usually stick to the basics with firewalls, but you can go about as complicated as you'd like. It's been a while since I've run Jinzora, but it was pretty sweet years ago when it was NetJuke, and since then too–even if they are offering support in a Second Life location. Weird. If you set up squid caching and have a wireless segment, make sure to turn stranger's images upside down. And upon some further research, some people are doing cool stuff with headless Ubuntu BitTorrent boxes.

And now I think it's time for me to go home and see if I can't get one or more of these actually running. Wish me luck!

Ubuntu Hacks: Flash, Java, e17 (from 2008/10/20)

This must be about the 1 millionth time someone's written a blog post about this, because I waded through a ton of them to get ones that worked. Which means someday, someone will be wading through 10 million websites trying to get their Flash, Java, and e17 working.

For the browser issues, I found this thread on the Ubuntu forums. In short, you download the first file listed(the Browser Install Script), untar it, and run it. It will download and install the 32-bit libraries, 32-bit browser, and plugins from the set of {Flash, Java, VLC}. The only trick then is rewriting your scripts to use firefox32 instead of just firefox.

To get e17 used to be a big pain. Even in Gentoo, you used to have to go to a lot of trouble to get e17 installed(I can't verify this at the moment, gentoo-wiki and gentoo-portage seem to be down). But it was really simple following these instructions: HOWTO: installation of e17 from SVN code

I'll post some screenshots or something later. It's pretty sweet looking. e17 has come a really long way.

Minor OS X Shell Shortcomings (from 2008/10/19)

In spite of the fact that a lot of people seem to loathe the colorized ls functionality, I sortof grew up on it(so to speak). OS X, by default, does not have this functionality(well, at least, GNU's –color option never works). I figured the quick and easy way to solve this was to install coreutils, but I found another option. It appears OSX included a version of ls that works with ls -G. The coreutils one is (by it's virtue as a GNU tool) probably more feature-driven, but realiasing it as <blockquote>alias ls='ls -G’</blockquote> is probably a little easier to swallow, and certainly faster if you're not a die-hard fan of some certain functionality in coreutils ls.

In other news, it finally really bugged me that OSX didn't have a watch command. There's sortof all kinds of stupidity about this floating around too, but I couldn't find a good way to get it without recompiling. The watch program resides in the procps package for Linux, and you can download it here. Once you've downloaded it, open a command window and type in:

tar xzf procps-3.2.7.tar.gz; cd procps-3.2.7
cat make.patch | patch
make watch; cp watch /usr/local/bin

And then enjoy your watchy-goodness. And maybe delete the tarball and the associated directory. Oh, and make.patch is there for ya.

Themes! (from 2008/10/15)

In all of my time with wordpress, I've pretty much stuck to the default themes, figuring that what I had to say was a bit more important than what I was doing with it. But then I came across one with some fluid dynamics going on… and I couldn't pass it up. Maybe someday I'll get around to throwing some of my own graphics up there, hehe. Enjoy!

Backposts Galore! (from 2008/10/14)

Like I said in ’ traviscj/ lives!’, I was stupid and forgot the hard drives with my websites on them at home. But….. Google Cache came through and I just pulled all my posts from that. The big downside is that there's now definitely going to be some weirdness with overlapping posts and soforth, which is a pain, but I'm not really sure how to get around it, other than just waiting until I can get the data off the disks again. So, if you came across my page from an old link, you probably won't see what you're expecting, at least until Google Cache re-pulls everything. I don't think too many people have linked to me, which is actually a good thing this once, I guess. In any case, I have the dates, titles, and posts. Sorry I lost your comments, feel free to re-comment at will!

traviscj lives! (from 2008/10/13)

I finally got my blog running again. I don't have the old data… oops. Forgot it at home. But in the mean time, at least I'm hosted again!