Category Archives: Maths

Nifty: Force Directed Graphs in Javascript

Starts off as a mess, then...
Kyle Scholz has developed code to represent Force Directed Graphs in Javascript, and you can interact with the nodes. We’re talking mathematical directed graphs here – you might know them as networks.

Basically, there’s a bunch of nodes and they settle themselves into a stable state minimizing tension between them – the graphs balance themselves out, and you can see it happening – it’s animated. And interactive – you can grab a node and move it around. It is ubercool.

Downside is that it sucks huge CPU.
... eventually becomes balanced

Sucky factorial calculators

Look for “factorial calculator” on Google and you’ll take a long time to find a factorial calculator that thinks that 100! doesn’t have an ‘e’ in it. If you’re going to write a dinky little app like that, be aware that there are limitations to it and tell people. I’m not going to link to any of them, they’re all naughty applications that shouldn’t be allowed out in the real world. But Dima Stopel’s large number factorial calculator isn’t afraid to give you all the digits.

Pi day

US-based mathmeticians celebrated Pi day on the 14th of March (in US-speak, 3/14). Note sure what those of us in the rest of the world should do… either accept the warped US standard for writing dates, or compromise on the accuracy and celebrate on 22nd of July instead.

See also: 75 digits of Pi, in MP3 format

75 digits of pi

(Does this count as a podcast?)

When I was a junior geek of 14 or so, some friends and I spent some time filling dead time in a maths class by learning digits of pi. I got to 75. Twenty years later, it’s still hanging about in my brain, wasting valuable brain cells.

Thank goodness it’s knowledge that is useful, rather than some pointless weird-arse geek party trick.

Click here to listen to 75 digits of pi. (171Kb, MP3, 21 seconds)