The earliest memory I have of ‘programming’ is in the early/mid 90s when my father brought home a computer from work. We could play games on it … so of course I took the spreadsheet program he used (LOTUS 123, did I date myself with that?) and tried to modify it to print out a helpful message for him. It … halfway worked? At least I could undo it so he could get back to work…

After that, I picked up programming for real in QBASIC (I still have a few of those programs lying around), got my own (junky) Linux desktop from my cousin, tried to learn VBasic (without a Windows machine), and eventually made it to high school… In college, I studied computer science and mathematics, mostly programming in Java/.NET, although with a bit of everything in the mix. A few of my oldest programming posts on this blog are from that time.

After that, on to grad school! Originally, I was going to study computational linguistics, but that fell through. Then programming languages (the school’s specialty). And finally I ended up studying censorship and computer security. That’s about where I am today!

But really, I still have a habit of doing a little bit of everything. Whatever seems interesting at the time!

A needle in a Pi-stack

2012-09-16

Recently I’ve been watching a lot of find-in-pi source code (require racket/generator) (define (make-pi-spigot) (generator () (let loop ([q 1] [r 0] [t 1] [k 1] [n 3] [l 3]) (if (< (- (+ (* 4 q) r) t) (* n t)) (begin (yield n) (loop (* 10 q) (* 10 (- r (* n t))) t k (- (quotient (* 10 (+ (* 3 q) r)) t) (* 10 n)) l)) (loop (* q k) (* (+ (* 2 q) r) l) (* t l) (+ k 1) (quotient (+ (* q (+ (* 7 k) 2)) (* r l)) (* t l)) (+ l 2)))))) Simple enough to use, we can use Racket’s for to generate a list of n digits of pi or to convert the same to a string:

Expanding L-systems

2012-09-15

An L-system is essentially a set of rewriting rules that turns a simple set of rules into a complex pattern. They’re generally used for generating self-similar fractals, including plant life, but I’ve also seen them used in programming languages research where they can generate valid programs given the grammar of a language. They’re also rather similar to turtle graphics in that many of the sample graphics that I’ve generated in the past are based directly off the L-systems page on Wikipedia. So this time I’ve decided to work on a relatively simple macro that can be used to expand simple L-systems.

Optimizing Voronoi

2012-09-13

Starting with my previous post on Voronoi diagrams, I felt that I could do better. Sure, the code works well enough but it’s almost painfully slow. So let’s see if we can optimize it a bit.

Fun with turtle graphics and stars

2012-09-10

After Saturday’s post on using turtle graphics to draw letters, I wanted to get back into drawing some fractals. Fractals are cool.

Generating Voronoi diagrams

2012-09-09

I was playing with image library and started to think about more ways that I could generate images. One idea that came to mind was to generate a bunch of colored points on the image and then color every other pixel based on which seed point was closest. Turns out, that’s exactly what a Voronoi diagramis… The Wikipedia article at least says that Voronoi diagrams can be traced back at least to Descartesin 1644, so I guess at least I’m in good company. 😄

The First Two Problems

2012-09-08

Anything worth doing is worth over doing, right? This time we have another two problems from Programming Praxis, aptly title “Turtle Graphics instead of just printing the characters. 😄

Generating epubs

2012-09-06

As I’ve previously noted, I’ve been writing a fair bit recently. Everything that I write is stored in a series of plain text files (actually here and it requires the here.

Backing up Google Reader / Calendar

2012-09-05

Similar to my previous post about backing up Gmail, this time I want to back up my here, from there it should be easy enough to derive the one for Google Calendar. First, we have the same setup as last time. Yes, I’m still storing the passwords in plaintext. Perhaps I’ll write up a way to avoid this in the future. #!/usr/bin/env python import urllib, urllib2 username = '#####' password = '#####' For the next step, I’m going to fetch Google’s login page using urllib.

Backing up Gmail

2012-09-03

A little while ago, I decided to finally get around to backing up everything. I’m pulling all of my files from both my website and the servers on campus to my desktop at home, backing my desktop up to an external hard drive, and pushing those backups to an offsite location. The former two steps are using here. First, some basic setup. Of course, I’ve blanked out my own username and password.

Wombat IDE - The return of screen sharing

2012-08-31

I’ve been working the last few days to get screen sharing working again and I think I have something. Again. Hopefully. The first idea was to use a UDP multicast network but when router configuration on campus got in the way, I moved back to a more direct TCP-based system. Still, I think it works pretty well.