## Archive for the ‘Boris Bikes’ Category

### A Treemap to find a rental bike in London using Processing

August 30, 2010

I was recently searching the web for news stories about the new rental bikes in London. In the process I stumbled across an API, produced by Adrian Short.

Upon seeing this data I had an epiphany!!! I have come across numerous APIs in my travels of the web, but I realised I could do something with this data!

One of the comments journalists have made, along with a few friends, is that either trying to locate a bay of bikes, knowing if there are any bikes available, or if there is room to park your bike when you get there. Here the treemap comes into its own.

Some background on treemaps (for those who don’t know): “Ben Schneiderman, of the Human-Computer Interaction Laboratory (HCIL) at the University of Maryland, worked out a set of algorithms to subdivide 2D space to show the relative size of files and directories (see http://www.cs.umd.edu/hcil/treemap-history). He call the representation a treemap, referencing the two-dimensional mapping of tree structures.” [quote taken from Ben’s book]

I had the idea from Ben Fry’s book Visualising Data in which he uses Ben Shneiderman’s Treemap software (which I have also utilised) http://www.cs.umd.edu/hcil/treemap-history.

Before visualising this data as is, I decided I wanted to create a top layer, that is the location (i.e. North, East, South, West) of London you want to investigate, and when you drill in you can then view all of the regions in that location, and then you can drill in further to see the specifics. For each level I decided to have a info box follow the mouse point to give the full details of what you were looking at. Remember the size of the rectangle represent how full the dock is, if it is full of bike the rectangle is large, if it empty of bike the rectangle is small.

To drill into the data Left Mouse on the Party which will take you in a level. To return a level, or more, Right Mouse Click.

I can’t thank Adrian Short enough for this, Boris Bikes for hosting the link to the API, and the Processing project.

I really like how it looks (no surprise there!)?

As ever this is a working prototype and I would interested to hear any feedback? Of course, because this is a Processing Application it is a Java Applet and because the applet is accessing the API it needs to be signed. You will have to allow access for the applet to work. Have a play (http://bikefacts.co.uk/Processing/Boris/inde.html).