I'm David Llewellyn-Jones and this is my homepage. I'm a software engineer at Jolla, who's also interested in programming, security, privacy and graphics. I occasionally crave adventure and a good thunderstorm. You might be interested in my software, my research or my random musings.

Want to know more about me? Here's a personality sketch written by a psychologist when I was in school.

“David is of high intelligence, although lacking in true creativity. He has a need for order and clarity, and for neat and tidy systems in which every detail finds its appropriate place. His writing is rather dull and mechanical, occasionally enlivened by somewhat corny puns and by flashes of imagination of the sci-fi type. He has a strong drive for competence. He seems to have little feel and little sympathy for other people and does not enjoy interacting with others. Self-centered, he nonetheless has a deep moral sense.”

Wow. Harsh. But disturbingly accurate.

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19 Nov 2019 : Graphs of Waste, Part 2 #
Part 2 of my series on embellishing histograms is now up on my blog. This post discusses a "continuous histogram" visualisation. It discusses how can you take data that accumulates over time that might usually be presented in a histogram, but instead render it using a continuous line without misrepresenting the data.
16 Nov 2019 : Waste data #
I've added another week's worth of data about my waste and recycling to the waste page. I made the mistake of trying to make Turkish Delight again this week (sadly still without any decent results). So, lots of grapefruit skins weighing down the compost. More concerning is that my general waste — the most damaging category — is up on last week by a big margin. It sounds terrible, but most of that was because I've been suffering from a bad cold and went through several packs of tissues (in Finland they come in packs, not boxes). Nobody benefitted from that! If you're taking an interest in my waste output, you might also be interested in my series of posts about the waste graphs I'm using. Part 1 is on my blog.
12 Nov 2019 : Graphs of Waste, Part 1 #
Over the next four weeks I'll be posting a series of articles on my blog about how I'm improving the graph on my waste page. The current graph is bad and needs fixing, and in the articles I plan to describe how. The first part entitled "Choose Your Graph Wisely" is now up on my blog.
10 Nov 2019 : Waste data #
I've added this week's waste measurements to the waste page. This week I tried to make Turkish Delight, which involved squeezing five big ol' grapefruit. The massive increase in compostable waste is down to the leftover grapefruit skins. Unfortunately the Turkish Delight turned out terribly. I'm now eating it as jam instead.
5 Nov 2019 : Bonfire night #
It's bonfire night in the UK (to celebrate the failure of the Gunpower Plot to blow up the House of Lords in 1605) and since I'm missing all the pyrotechnic fun (Finland has other stuff to celebrate) I've added some fireworks to the background of the site instead. Thanks go to Martijn Steinrucken (aka BigWings) for making his great shader available under a CC BY-NC-SA 3.0 licence.