I am David Richfield, a German chemical engineer / biochemist born in South Africa. I'm a founder member and former director of Wikimedia South Africa, the South African Wikimedia Chapter. I also created the parliament diagram tool, which is widely used to create diagrams for political articles on Wikipedia.
My username comes from IRC: "/me" is a shortcut which inserts your username.
I enjoy learning languages, graphic design, 3D modeling with Blender, cartography on OpenStreetMap, computer programming, playing Go and promoting free software. In 2016, I started juggling.
Here's a Limerick:
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3
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cos
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{\displaystyle \int _{1}^{\sqrt[{3}]{3}}\!t^{2}\,dt\cos({\frac {3\pi }{9}})=\ln({\sqrt[{3}]{e}})}
David Richfield
I am David Richfield, a German chemical engineer / biochemist born in South Africa. I'm a founder member and former director of Wikimedia South Africa, the South African Wikimedia Chapter. I also created the parliament diagram tool, which is widely used to create diagrams for political articles on Wikipedia.
My username comes from IRC: "/me" is a shortcut which inserts your username.
Here's a Limerick:
∫
1
3
3
t
2
d
t
cos
(
3
π
9
)
=
ln
(
e
3
)
{\displaystyle \int _{1}^{\sqrt[{3}]{3}}\!t^{2}\,dt\cos({\frac {3\pi }{9}})=\ln({\sqrt[{3}]{e}})}
I started work a while back on a tool to render svg diagrams for legislatures - I started out with a tool that spits out a rectangular diagram with a title and a legend. In May 2010, I saw some very nice arch-shaped diagrams drawn with User:Habbit's ADSvote program requested for conversion to SVG on WP:GL/I. Instead of doing manual SVG conversion, I programmed a similar algorithm, which I now host on Wikimedia's Toolserver (link above). The source code is hosted at GitHub - Bug reports, feature requests and patches are welcome!
The arch tool is quite popular for election results on Wikipedia, but the Westminster-style tool is still under development: a standard style has not yet been clarified, so if you use it, expect criticism and/or correction. If the output is not as you expect, consider editing with Inkscape and saving the result as a "plain SVG".
You can also upload the diagrams directly from the tool. You can see the most recent uploads here.
Here are some selected files. For a more complete list, with many more pictures, see my Commons uploads (or if you have javascript enabled, you can see them in a gallery view)
The main steroidogenic pathways. I made the first version of the svg from scratch; expanded, coloured and successfully shepherded through the featured pictures process by User:Mikael_Häggström.
I bought a Canon PowerShot A630 in April 2007, and have since started contributing photos to Wikipedia. In 2008, due to an insurance payout after a stupid accident involving seawater, it was upgraded to an A650IS, which runs CHDK, which greatly increases its flexibility. That camera was stolen in 2013, and I replaced it with an SX270HS, which at the time didn't run CHDK.
In 2014 I bought my first DSLR, a Canon EOS 600D. It's a very nice camera! I had good success with macro photography using extension tubes with the stock lens, but I later also bought a Tamron AF 70-300mm combination macro/telephoto lens, which gave me good results until 2025, when the connection between the lens and body became dodgy, and I wanted a new camera anyway, so I upgraded to a Canon EOS R7. It's a very nice camera! The stock lens on its own is excellent and quite flexible, and the camera's IBIS together with the lens image stabilisation gives great hand-held performance. There is no noticeable lag on the electronic viewfinder. Having a connection to my mobile phone for remote shooting and for direct import of snapshots that I don't want to work up in darktable is also great.
![{\displaystyle \int _{1}^{\sqrt[{3}]{3}}\!t^{2}\,dt\cos({\frac {3\pi }{9}})=\ln({\sqrt[{3}]{e}})}](https://wikimedia.org/api/rest_v1/media/math/render/svg/80c49530b051178829b90a3bf2db365b916d875c)
Schematic diagram of the House of Lords, showing government, opposition, cross-bench and speaker
Arch version
Another arch
A small sample of boleite photographed at the Museum Reich der Kristalle in Munich.
The main steroidogenic pathways. I made the first version of the svg from scratch; expanded, coloured and successfully shepherded through the featured pictures process by User:Mikael_Häggström.
A W-type external-thread collet being pulled into its spindle seat with a drawbar, clamping and then releasing a shaft.
Life cycle of Echinococcus
Lots of thumbtacks, just for fun!
An old Cadmach tablet press
Round, biconvex white tablets
Tablet failure modes
An empty pycnometer
A full pycnometer
Laboratory distillation set-up
Red and white deposited hard candy
Animated SVG: the rotors of a three-lobe Roots blower meshing and rotating.
Two snails investigate each other before mating
A specimen of Duberria lutrix
Green insect eggs found on a curtain
A sundew in Jonkershoek, Stellenbosch
A cockroach in Jonkershoek, Stellenbosch
The Painted Tree Frog
Parapioxys jucundus
The P450 catalytic cycle - thanks to User:Rob Scarrow for the correction!
Stress vs Strain graph: re-drawn with actual stress line added
Stanley Bridge in Alexandria by night during Ramadan 2009
A graffito of Riaan Cruywagen
An SVG icon for manufacturing company stubs
Baseball stub template pic, built from parts
