So, I finally got fed up with never having a screwdriver when I needed it unexpectedly. Perhaps this was due to the recent MacGyver watching binge, but either way, I’m calling it excess frustration. It seems like it always throws me off when I’m trying to do something at work or at a friend’s house to their computer or… whatever. I had started to carry my little red Swiss Army knife a while back, and it came in handy at least a couple of times a day, so I decided it was probably worth further investment to get one with a real screwdriver on it.

I’m a little bit late announcing this, but…. I BOUGHT MY BRAZIL TICKETS!

It ended up being like 1300 bucks, and I have a 13 hour layover in Atlanta on the way there…. but I think that’ll be okay. It’s actually enough time that I think I might go in and see the world’s largest aquarium, the CNN headquarters, and the World of Coca Cola.

We’re going to be staying somewhere called El Misti Hostel, and make up about 70-80% of the residents there. It’s right off of Copacabana Beach, which is very, very exciting.

I’ve realized that a lot of people are nervous about differential equations. Which is understandable, but in general there’s some pretty straightforward ways to solve a fair number of the ones you come across. I’d really like to write some of it up.

My basic idea is going to be, show a bit about integrating factors, a bit about separation of variables, the characteristic equation, and the method of undetermined coefficients. That covers a lot of physical territory. Then some about reducing order with transformations from n-th order equations to n 1-st order equations, and basic Laplace for a sortof general method. And finally, maybe a tiny bit about numeric methods.

After I had finally convinced myself to get out of bed this morning to go to my ACMS seminar, I quickly checked my email and my heart sank a little. Today’s talk was on SAGE. Don’t have anything against SAGE, but I thought it was just a big pile of open source packages in a big, heavy install. Sorta cool, but worthless, in other words.

Turns out, I was pretty wrong about that. It is that, but it’s also 70k new lines of code that does a whole bunch of exciting stuff. Near the end of his talk, William Stein mentioned that they had created a new tool called Cython. (Well, extended Pyrex, but… whatever.)

No, not that dizzy, spinning sensation. The Firefox extension.

Someone finally caught on to the fact that on a lot of modern computers, we have a lot more horizontal space than vertical. Whoever it was, they must have also been miffed that they never seemed to have room for all of their firefox tabs. So, they made a vertical tab menu, which is actually pretty cool. The standard stuff (ctrl-tab) still works, which is convenient.

I’ve been playing around with Python a bit more over the break, mostly because I want to be lazy in my code-writing for the forseeable future, plus I’d like to give NumPy a shot, but I want to have a solid background before trying that. One thing that just has not gotten old yet is the ability to assign functions absolutely anywhere in python. You can pass them around like variables, put them in dictionaries, return them from functions, whatever. I mean, I lived in parenthesis for a while in my scheme class, so it’s not like I haven’t been exposed to it, but it’s still damn cool. You can do cool stuff like making a tuple of some index, some value, and the function to process the other two. That makes it so much easier to deal with various combinations of neat datastructures. Anyways, the book I’ve been reading is Dive Into Python, off diveintopython.org. I’m currently at about page 114 out of 327, and I’ve fairly faithfully read most of it up until that point. The format seems slightly frustrating to me, but it’s probably just because it’s such a departure from what a lot of books and tutorials use. It seems helpful and worthwhile in any case.

TrueImage is… well… Quite the piece of software.

What I need it to do: Tell the check_backupdisk script that it’s actually running the backup (IE–don’t bitch on nagios) and handle all the mounting/umounting/fscking that it currently does. I think I’ll probably end up putting a wrapper script around it…. but we’ll see.

So, another day, another (minor) problem. I had connected to a server with KDE instead of our usual GNOME interface. Which probably would have been fine except that KDE had a screensaver that sucked up the CPU. Which also would have been fine, if it hadn’t been a server that everyone else used. Oops. RRDtool and MRTG would have shown a CPU spike which I could have investigated.

So, rrdtool is pretty sweet, but it’s somewhat of a pain to set up. So… we use Cacti. It’s amazing. Supposedly it’ll integrate with Nagios as well, and then all of this data will be at our fingertips. For now, I just set it up on my server that’s probably going to go down shortly. In any case, I feel like this project is somewhat coming together. Nagios is great for what’s going on right now, cacti needs a way to know what’s going on right now–A match made in heaven, or something.

I have apparently been missing out. There’s a really neat little unix tool called ‘rrdtool’ that uses a fixed-size database to look at how something changes over time. I think I’ll use it to monitor server load… and possibly network traffic.