Markov Chains

This is an amazing visual explanation of Markov Chains, built using D3. I really like the way the playground works. It lets you generate your own chains and watch as the complexity increases as you add more states.

To be fair though, I tend to enjoying¬†watching D3 rendering algorithms generally. Its cheaper than satellite TV and works on my phone too ūüôā

Thank you to Brian for the link.

Screen Shot 2014-07-31 at 2.02.39 PM

Raspberry Pi Wall Display

May was an interesting and fun month. I finished a project to build a big 3 x 3 TV wall display to be used at a call centre for the 2014 elections.  The requirement was to have 9 screens all operating independently that can have individual images sent to each screen or a single image zoomed across all 9 screens.

Pi Wall - Per Screen  Pi Wall - Zoomed

Continue reading “Raspberry Pi Wall Display”

Mapping Runners

comradesI do occasional Park Runs and trail runs. On a recent run I started to wonder what the distribution or histogram of runners looks like. It would be a big moving blob at the start that slowly thins out as the faster runners pull away from the slower runners. The shape will depend on the race distance and the number of runners. I first did it for the Comrades Marathon in 2014, and now again for the JP Morgan Corporate Challenge. The shape will depend on the race distance and the number of runners. Continue reading “Mapping Runners”

Making a Cartogram

Mike Bostok has a fantastic tutorial on how to make a map¬†using d3 and topojson. Having done some mapping work recently for a client, I was keen to learn more and try do a d3 based cartogram. I found some good examples of non-contiguous cartograms, but I wanted to make a South African version of a contiguous one using Shawn Allen’s d3 implementation.

Here is the final product, and I’ll take you through some of the tricky parts that I had to deal with.

Continue reading “Making a Cartogram”

Visualising a DDoS attack

The makers of the very awesome VLC media player were recently the subject of a DDoS attack. They made a video that visualised the attack using a program called Logstalgia. Its very pretty to watch.

It would be interesting to correlate this data with a location map to see just how widely distributed the attack was, similar to this one I built for the Security Presentation.

Census Data

Building the Census Data Explorer required that I have the South African Census data in a format that worked easily with D3, i.e. JSON. I therefore had to get the data from the Statistics South Africa website and convert it into JSON format. I’m making it available here for you to use. Its not complete, just the data I needed for this project.

South African Census Data in JSON format

Monitoring System Dashboard

three6five probe dashboard

Another three6five related project was the requirement to create a dashboard for our support team to have an overview of all the probes that we have deployed on site at our customers. Specifically it needed to firstly highlight any probes that are not functioning, and then any services on an active probe that are not functioning.

This will live on a big TV screen in our support centre and can be seen from anywhere in the office. While we send out notifications, its good to have a easy to view list of all the issues that are being dealt with. Continue reading “Monitoring System Dashboard”