Lab
Half notebook, half playground: small things I build to understand an idea by making it move. The first two are companions to posts, so you can ask the data your own question. Below them are a clustering algorithm you can watch settle and a puzzle that changes daily. Psst: type life, langton or turing anywhere on the site, or try the Konami code.
Your station's day
Blue: the station's flow per 15 minutes. Dashed: the whole network, scaled to the same peak. Hover, or focus the chart and use the arrow keys.
Powered by TfL Open Data. One modelled typical day; nothing between 02:00 and 05:00. Paddington's two Tube stations are combined here, so the list has 267 names for 269 stations.
Voronoi playground
Each cell is the patch of London closer to one plaque than to any other. Darker cells belong to plaques with a close neighbour. Click the map (or focus it and press Enter) to add a plaque, or try Random scatter to see what no clustering looks like.
Plaque locations from English Heritage, scraped August 2026 for personal, non-commercial use.
k-means clustering
Points snap to the nearest centroid; centroids drift to the mean. Watch it settle.
Puzzle of the day
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A fresh probability puzzle every day, the same for everyone. Type a guess, then Reveal to check. Come back tomorrow for a new one.