Hi, I'm Jonas.

Jonas Einarsson

I'm an engineering physicist with a knack for coding.

Check out some things I've made & written

Software for symbolic tensor algebra & calculus

Some of my research in theoretical fluid mechanics required large amounts of tensor algebra. I wrote some software to relieve the worst pain. Code and paper (arXiv).

Polar plotter

When I finally got a 3D-printer I just had to design a hanging V-plotter. Here's some pics and info.

Oldschool intro on Sega Master System (2003)

In my youth I was part of the demoscene, where I learned much about programming and obscure platforms. With an effort out of proportion to the result we created a one-screen intro that ran on a real Sega Master System. Click through for video and credits.

A biological computer and P=NP

I wrote a Letter to the Editor of PNAS about a mistaken claim of solving a NP-complete problem. It is remarkable that this mistake survived through editing & peer-review in a top journal. Read more →

Interactive fractal curve generator (D3.js)

Like most engineers I have an affair with fractals every now and then. This one coincided with learning D3.js and resulted in a surprisingly fun tool. Go ahead, try it.

Interactive fractal spiral generator (D3.js)

I made this because I toyed with the idea of decorative fractal patterns for the house. That never happened, but the tool exists. Check it out.


Me and three friends wanted to visualize the open data from the Swedish parliament, with lofty hopes of giving an unconventional view into the workings of power. Unsurprisingly it turned into 90% data cleaning and 10% visualization. The site is live although we did not clean the data for the last few years :( Code and site

Visualizing paths as flows in a Sankey diagram

When building demokratikollen.se I wanted to visualize the paths of proposals in the Swedish parliament, from a source (e.g. a party), through a committee (e.g. the tax committee), to a decision by vote (yes/no). Read about my solution here.