# teaching machines

## Coscars

Something came in the mail this week from the University of Canterbury in New Zealand. The Department of Computer Science and Software Engineering (who use COSC as a prefix for their computer science courses) just held their end-of-year awards ceremony, the COSCARs. I was honored with this Most Wholesome Lecturer award: How exactly I was […]

## Cutting Corners

I learned recently of Chaikin’s Algorithm, a method for rounding off the corners of a polygon. The algorithm works like this: Find the midpoints of each line segment in the polygon’s perimeter. Connect each consecutive pair of midpoints using a quadratic Bezier curve. The midpoints are the curve’s endpoints. The vertex between them is the […]

## Circle Dance

At one time, people believed that the Earth was the center of the universe, and that the planets and the sun orbited around it. Copernicus came along and challenged this idea, suggesting that the sun was the center. These are the only two sides of the debate that we ever hear about. Heliocentrism vs. geocentrism […]

## Background Check

There’s somebody on Twitter named Dave who makes animations that break your mind. I fell in love with a simple rotating one a couple of weeks ago and recreated it in Twoville: Several others have recreated it too, but they appear to have fallen for the same trap that I initially fell for. They enumerated […]

## Progress in Twoville

Today was a non-teaching day, so I made some “progress” in Twoville: You could summarize my professional career as one long effort to get to the point where I can express non-trivial ideas about shapes and animations in around 30 lines of code that doesn’t need to be compiled.

## Triangular Colors

Last week I was trying to think of boolean predicates that I could use for exercises in an introductory programming class. I remembered the triangle inequality, which states how the lengths of three line segments must relate if they are to be formed into a triangle. In short, each segment must be shorter than the […]

## Power Set of Venn Diagrams

In our introductory programming class, I try to reframe abstract logic into concrete spatial thinking. One way I do this is through the game Trux Falsy. Another way is through Venn diagrams. I want students to see how the AND operator creates an intersection, how the OR operator creates a union, and how DeMorgan’s Law […]

## Terra’s Theme

I’m not exactly sure what Deltaphone is for, but this afternoon, it was for analyzing the structure of Terra’s Theme from Final Fantasy VI. (Thanks to 8-bit of 8-bit Music Theory, who did all the work.) The melodic line consists of a phrase repeated three times, and this phrase is expressed in the prefix function […]

## New Geometry

What do you call a portion of the shaded area between two arcs? A sharc. The figure above was created in Twoville, a little language for drawing vector art. Here’s the complete program:

## Little Notebooks

The best days are the days in which I write in a little notebook. The things I write are myriad: 20 drafts of a haiku, big goals for a project, a TODO list for the day, an outline for a lecture, a draft of a talk, a humorous thought, a record of a dream, an […]