David Johnstone

Things I've made

Cycling performance analysis

Cycling Analytics

This is a website I'm building for serious cyclists to track their riding. It's the ideal intersection of web development, cycling and analytical goodness for me to be working on.

David Johnstone's website


This is the website that you're looking at now. As you might be able to tell, this is where I keep a blog, make the occasional fancy web page, and might someday do a bit more.

Lch and Lab colour and gradient picker

A colour and gradient picker that uses a variety of colour spaces for choosing and interpolating gradients, including Lch and Lab.

Cubehelix gradient picker

A gradient picker that uses the cubehelix method.

Barnsley's fern on a HTML5 canvas

Barnsley's Fern on a HTML5 canvas. It's 180,000 green dots drawn using a simple formula, and it ends up looking quite nice.

Hash collision calculator

A tool to calculate the probability of a hash collision. It was meant to be a simple bit of code with lots of CSS to make it pretty, but that was before I started looking at JavaScript big number libraries…