Lindenmayer systems, or L-systems, provide a very powerful way to construct fractals. Lindenmayer used L-systems to describe the behaviour of plant cells and to model the growth processes of plant development. An L-system is a rewriting system and a …

## A Fake Circle made of Straight Lines

Inspired by this post on Reddit, I wrote this little script to do the same thing. The circle is an illusion created by 100 straight-line tangents to an invisible circle. The tangents are created by drawing a chord in a …

## Tweetable Python Code Golf

Code Golf is the amusement of writing as short as possible a program to perform a given task. So for example, if the task is to compute the average of a list of numbers (which could be changed at any …

## Random Walk

A colourful random walk. The basic idea is very simple: choose a random heading in the range 0:360 degrees. Step in that direction. Choose another random heading & step again. Do this 2,000 times. As a bonus, we go through …

## Turtle Star

A very simple Turtle program. Turtle can draw intricate shapes using programs that repeat simple moves.

Turtle graphics is a popular way for introducing programming to kids. It was part of the original Logo programming language developed by Wally Feurzig …

## Sierpinski Triangle, drawn by a Turtle

This is a classic fractal drawn with a recursion algorithm and Turtle graphics. The Sierpinski Triangle’s sides are bisected and the triangle they form is removed. The procedure is then applied to the 3 remaining triangles, and to them recursively …

## Square Spiral

This is a very simple introduction to Turtle graphics. The turtle starts in the middle of the window, moves forward a small distance, turns right, moves forward a slightly longer distance, right again, even further this time… until the distance …