Tools & Experiments

by Peter Collingridge
My sister's handmade cards on Etsy.
Drawing of a pile of animals

You can find out more about me on my other blog. If you have any comments or feedback please contact me.


Currently only one tutorial at the moment, but I'm hoping to move some over from my old site and write some more when I get the chance.

3D graphics tutorial

A step-by-step guide in how to create your own 3D graphics engine. It uses Khan Academy's computer science platform, but the principles apply to any computer graphics system.


Various tools written in Javascript or Python. Most of them are quite experimental.


Javascript program to reduce the file size of uploaded SVGs.


Experimental Javascript program to view SVG code (and reduce the file size).


Javascript program to apply transformations to SVG elements and to convert between abolute and relative paths.

Matrix multiplier

Uses jQuery and Javascript to immediately display the result to multiplying two matrices. Eventually I hope it will be able to mutliply matrices containing variables as well as numbers.


Uses JQuery and Javascript to convert pinyin written with tone numbers (e.g. ni3hao3) into piyin with tone marks (e.g. nǐhǎo). Eventually I hope to add the ability to convert hanzi to pinyin, but I need to find a good dictionary.


A Python program that pixelates an uploaded image such that details are preferentially preserved. Outputs a HTML5 Canvas image and processing.js code which can be directly used in Khan Academy's computer science platform. (Currently out of service)


Bioinformatic tool that displays basic information about DNA or protein sequences. Uses Javascript and aims to give instant information as soon as sequences are added.

DNA images

A Javascript program to generate SVG images of DNA, especially for illustrating PCR.