Sunday, August 2, 2009

Introduction to Programming Using Python

Just under a month ago I tossed the idea around of running a Saturday course to teach high school kids some programming. The idea was to take the new batch from the UCT Maths Circle and give them some exposure to programming and introduce the keen ones to our UCT Algorithm Circle. Back then I had no idea it would turn into this:

When I realised the number of new kids coming from the UCT Maths Circle might be too small, I decided to open it up for application from anyone with limited or no programming experience. All we asked for was a 100 word motivation of why they should be invited and an optional recommendation from a teacher to strengthen their application. I approached the Computer Olympiad office for a list of email addresses and postal addresses of the schools that had entered the Computer Olympiad before. We emailed about 90 schools and posted to about 60 schools with no idea of what to expect.

The advertising was sent through during the school holidays, so nothing really happened for some time. When schools started on Tuesday 28 July though, they started coming in slowly and some of the applications looked very promising. It was around this time that I started thinking of how many we could accept: I settled on 30 and asked 3 other students to help lecture/tutor. By the end of the first week of school though, applications had started flying in like mad. By the end of Monday we had received about 60 applications and they were still coming in. If we stuck at accepting 30 we would have had a shit time turning away some strong applications. Rob to the rescue as we got a fourth lecturer which allowed me to increase capacity to 40. More kept rolling in, including one application arriving on the morning of the course!

We eventually ended up inviting 46, with the expectation that at least 5 wouldn't pitch. We underestimated their enthusiasm: one fell ill, another had a last minute commitment; everyone else pitched! Even after the first day, only one kid fell ill and the rest all returned. Unfortunately a group of four girls had to leave early to catch a lift and another left as she was falling behind. Everyone else stuck it through the whole way. Not something I could possibly have expected! But it means we did something right, right? :)

We chose to run the whole course in the computer lab so that they could run short examples as we taught them things. It really worked well as we could immediately see if they were struggling on something and we never once lost them badly. We could get them to run bits of code to see for themselves what they did and then expand on how it worked.

Taking a step back a bit, on Thursday morning I got a bit of a scare. One of our lecturers had caught a bad dose of the flu, so I ran around trying to find a replacement. Fortunately some students lurking around in the Computer Science building at the time offered a hand and I split the load across three of them. I thank them all mightily for helping out at such short notice. They did a fantastic job, as did all the others that gave a helping hand. In the end it was myself and Michiel Baird doing all the admin work; the two of us, Ben Steenhuisen and Julian Kenwood doing the lecturing; then Jason Brownbridge, Bertus Labuschagne and his brother Phil and Kosie van der Merwe helped out with tutoring, answering the kids' questions; Brent Benade helped order pizza for everyone, a rather nasty job.

When the kids started arriving there was quite a lot of tension in the air, which was to be expected. We planned for this and tried to make sure that we had at least two from each school, so that there was a good chance each kid knew someone else. A number of our lecturers and tutors are great at throwing humour around, which helped ease the tension really well. By the end of the first day (3 hours) most of them had opened up and had no problem asking for help.

The topics we taught, in the order we taught them:

  1. What is programming?
  2. Using the Python interpreter
  3. Input and output
  4. Variables, operators and basic data types
  5. Boolean expressions and conditionals
  6. While loop
  7. Lists
  8. For loop
  9. Strings
  10. Writing functions
That was all covered in 9 hours. Bear in mind that these are grade 7, 8 and 9 kids (and a couple grade 10's) with mostly no prior programming experience at all! Now read the list above again. From what I can remember of my high school experience, what we taught them in 9 hours was equivalent to what is covered in the entire grade 10 and 11 IT syllabus minus files and gui's, and obviously all the theory crap.

They all did exceptionally well. Now it's time for them to write the test we gave them and we'll invite the best ones to attend weekly 90 minute classes to further teach them more on programming, especially focusing on improving their problem solving skills. What's great for them too is that they also have the opportunity of being invited to UCT Maths Circle, our partner in crime.

There is one thing we feel exceptionally guilty about. We received over 80 applications, but only had space for 46. Reading each and every one of those motivations of the kids we had to turn away makes me feel very sad. Therefore there is the possibility of us running another course like this in the near future. If you are interested in attending a future course, please contact me. We also run another class on data structures and algorithms for those who have a strong grasp of programming, are bored in class and want a challenge.

Sunday, February 1, 2009

UCT Algorithm Circle

After much grinding away, we had our first class of the UCT Algorithm Circle this past Thursday. We invited 32 of the most talented school kids we could find in the Cape Town area and invited them to some training. We're also slowly inviting kids outside of Cape Town to train online. We're teaching them from the very basics of programming right through to the advanced algorithms and data structures required for the IOI.

For the first class, we introduced the basics of Python. We were amazed at how quickly the kids caught on. After a 20 minute lecture and 60 minute practical session they were understanding operations, variables, stdio and more. The majority of these kids are in grades 9 and 10, and amazingly half are girls.

If things continue at the rate they're going now, this could provide a serious boost to our IOI results in upcoming years. We've always been welcome to the idea of training a wider audience, but finding the talented kids and getting them interested has always been a brick wall we couldn't knock down. This time though, collaboration with one of the people involved in the teaching kids for the IMO has seriously helped change all that.

To see the kids we have, just check out some of their introductions in this thread to see what they're capable of.


After completing the meat of my background chapter in December, I spent the most part of January working on a prototype for my masters project. So now I get to start showing off all my pretty pictures. :)

First of all, I should mention that I am writing an extension for VMD, so I most certainly did not develop what you see below from the ground up. In an effort to simplify the process of porting my work to other molecular visualisation applications (e.g. PyMol), I decided to do all the core computation in an application-independent C++ module which communicates with an application-specific plugin via sockets. For VMD, this plugin is written in Tcl, which I have come to hate.

When you first launch VMD, you get a simple protein. Launch my extension and it churns away, calculating conservation scores (dummy values for now) and the solvent accessible surface of the protein. The protein is then coloured based on the conservation scores, which you can see below for a sample protein.

After visualising the conservation scores, the final application will visualise its prediction of binding sites. The user will then be given the option of doing further analysis of the binding sites. We're currently considering two forms of analysis: select a residue and predict what a binding site containining this residue would look like; and select some residues and predict what the binding sites would look like if we excluded these residues from the predicted binding sites. Below is a sample of user-selected residues (in red).

Then the user can choose to visualise the solvent accessible surface. We calculate this surface using marching tetrahedra to extract an isosurface and kd-trees to calculate the isovalues. The surface is coloured by the conservation scores, just like in the previous shots. Currently I don't have residue selection working in this mode, although I plan on doing so. The meat of my computation will be using the conservation scores and the solvent accessible surface to predict the binding sites.

Then finally, VMD is a very feature-full tool and least of which you can do is rotate the protein for a view of the entire protein as you can see below. There is much more you can do with it, but I'll leave interested readers to explore themselves.

Next week I'm off to the Afrigraph Conference in Pretoria, after which I have to attend this 6 week bioinformatics course in Stellenbosch. Lectures 09:00-18:00 every day for 6 weeks. Not sure how I'm going to last.