Skip to main content

Computer Science: Faster, Smarter, More Robust

My wife and I like to play video games together cooperatively. Generally, she plays the exploratory parts, and I play the parts the require quick reflexes.

Recently, we've been enjoying a game called iNinja for the GameCube. (Thanks Ben Bangert!) As we neared the end of the game, we reached a level called "Egg Shell Skull" that seemed impossibly hard. We each spent a couple hours trying to beat it, but to no avail. It required 100% accuracy, very fast reflexes, and a little bit of multitasking. I could "program myself" to have fast reflexes with high accuracy, but every time I mixed in the multitasking, my reflexes went out the window.

Finally, I had the idea of playing the level together. I used the left side of the controller which involved ducking with 100% accuracy and very fast reflexes, while she focused on the right side of the controller which involved planning, combos, and monitoring a timer. After several tries, we finally beat the level :)

Since this is a purely technical blog, you might have guessed that I'm not trying to focus on how great a gamer I am ;) I'm trying to point out something. In a real-time system, you don't always have enough clock cycles for the best algorithm possible. That's doubly true for "coding in wetware". I was able to program my brain to have high accuracy and low latency, but only if the task was very, very simple. There's just not much decision making you can do in low latency situations. This is backed up by what little I know about the amygdala and the neo-cortex.

There's another case of this pattern that I find enlightening. I saw a talk from an air traffic controller, and he was explaining that there are three systems that are used simultaneously to help planes avoid hitting each other.

There is a very stupid and robust system that kicks in when two planes are about to collide. This system is in charge of implementing the correct "duck!" algorithm. The next system is in charge of avoiding a "loss of separation" within the next 5-7 minutes or so. It's more complicated, but doesn't have to worry about wind, etc. The highest level system is in charge of avoiding a loss of separation in the next 12 minutes. It is extremely complicated, and has to account for things like wind, etc. These separate systems have separate code bases, naturally.

In the future, I wonder how often we'll see cases like this. Sometimes, neither the simple, fast, and stupid solution nor the elegant but complex solution will do the trick. Sometimes you need both--just like the human brain needs both.


Anonymous said…
Very nice entry. Interesting and an inspiration for a current little programming project of mine.
Cheers, Jan
writeson said…
Really like this entry, though it completely reinforces my belief that driving and talking on a cell phone are in a mutually exclusive domain. I've also read articles about the programs on the space shuttle being kind of like this; complicated, but short and only responsible for this range of five minutes before another program takes over.
Anonymous said…
It brings about a zen like realization...somethings like these are the ones that you think about, know about, yet when you read it in words, it does bring out something.
jjinux said…
Glad you liked it guys :)

Popular posts from this blog

Ubuntu 20.04 on a 2015 15" MacBook Pro

I decided to give Ubuntu 20.04 a try on my 2015 15" MacBook Pro. I didn't actually install it; I just live booted from a USB thumb drive which was enough to try out everything I wanted. In summary, it's not perfect, and issues with my camera would prevent me from switching, but given the right hardware, I think it's a really viable option. The first thing I wanted to try was what would happen if I plugged in a non-HiDPI screen given that my laptop has a HiDPI screen. Without sub-pixel scaling, whatever scale rate I picked for one screen would apply to the other. However, once I turned on sub-pixel scaling, I was able to pick different scale rates for the internal and external displays. That looked ok. I tried plugging in and unplugging multiple times, and it didn't crash. I doubt it'd work with my Thunderbolt display at work, but it worked fine for my HDMI displays at home. I even plugged it into my TV, and it stuck to the 100% scaling I picked for the othe

Drawing Sierpinski's Triangle in Minecraft Using Python

In his keynote at PyCon, Eben Upton, the Executive Director of the Rasberry Pi Foundation, mentioned that not only has Minecraft been ported to the Rasberry Pi, but you can even control it with Python . Since four of my kids are avid Minecraft fans, I figured this might be a good time to teach them to program using Python. So I started yesterday with the goal of programming something cool for Minecraft and then showing it off at the San Francisco Python Meetup in the evening. The first problem that I faced was that I didn't have a Rasberry Pi. You can't hack Minecraft by just installing the Minecraft client. Speaking of which, I didn't have the Minecraft client installed either ;) My kids always play it on their Nexus 7s. I found an open source Minecraft server called Bukkit that "provides the means to extend the popular Minecraft multiplayer server." Then I found a plugin called RaspberryJuice that implements a subset of the Minecraft Pi modding API for B

Creating Windows 10 Boot Media for a Lenovo Thinkpad T410 Using Only a Mac and a Linux Machine

TL;DR: Giovanni and I struggled trying to get Windows 10 installed on the Lenovo Thinkpad T410. We struggled a lot trying to create the installation media because we only had a Mac and a Linux machine to work with. Everytime we tried to boot the USB thumb drive, it just showed us a blinking cursor. At the end, we finally realized that Windows 10 wasn't supported on this laptop :-/ I've heard that it took Thomas Edison 100 tries to figure out the right material to use as a lightbulb filament. Well, I'm no Thomas Edison, but I thought it might be noteworthy to document our attempts at getting it to boot off a USB thumb drive: Download the ISO. Attempt 1: Use Etcher. Etcher says it doesn't work for Windows. Attempt 2: Use Boot Camp Assistant. It doesn't have that feature anymore. Attempt 3: Use Disk Utility on a Mac. Erase a USB thumb drive: Format: ExFAT Scheme: GUID Partition Map Mount the ISO. Copy everything from