## Spectral Harmonographs

5th October 2015

This Python + Pygame program draws the trace of 4 decaying sine waves, 2 per axis, with rainbow colours. It generates a sequence of random harmonographs. A harmonograph is a mechanical device typically seen in science museums, that has two or more pendulae with attached pens, that can draw on a sheet of paper. The pendulae are […]

## Harmonograph in Pygame

3rd October 2015

You may have seen those devices at the Science Museum or Exploratorium or Techniquest… There’s a drawing surface and some arrangement of pendula with a pen touching the paper on the drawing surface, set in motion it draws these pretty pictures, which are essentially decaying Lissajous figures. Lissajous figures are often seen in old sci-fi […]

## Stars and Stripes

4th July 2015

A variation on the Stars and Stripes American Flag for Independence Day. It’s an exercise in the use of transparency in Pygame. The stripes are made transparent so the stars image behind shows through.

## Animated Tower of Hanoi

3rd July 2015

The Tower of Hanoi is a classic problem that lends itself well to a recursive solution. The story involves some poor monks having to move 64 disks of different sizes (with central holes for the pegs) from one peg to another. There are three pegs, all the disks started on the first peg (in size […]

## Rainbow Flag in Pygame

29th June 2015

This little Pygame program paints the Rainbow Flag, as used by the LGBT movement. It illustrates: Importing the Pygame library RGB colours in hexadecimal Python’s for loop using the enumerate() function Filling a rectangular area in Pygame Updating display with flip() Saving the image

## A Graphical Dice Simulator

31st May 2015

This PyGame program simulates the roll of a die (or dice if you prefer). It’s a fairly simple, straightforward thing to do, though it may be worth noting that the spots display is oh-so-slightly clever. Some spots appear in more than one number, e.g. the middle spot is in all the odd numbers, hence the […]

## Fast Mandelbrot Set by QuadTree

27th May 2015

Most Mandelbrot Set programs proceed along the display area, pixel by pixel horizontally, row by row from top to bottom. This one doesn’t. It divides up the screen into 6 horizontal squares in 2 rows, then for each one, checks the value of the escape time for the pixel at each corner. If they’re all the […]

## Naive Mandelbrot Set

17th April 2015

This is your basic Mandelbrot Set plotter. Very little effort made to speed it up, except for plotting top & bottom pixels together as they’re mirrored across the x-axis. Later I’ll show you some much faster programs! The heart of this program is the iteration of z2+c where c is a point in the complex […]