Trying to get my head round what to talk about in another couple of presentations – an online viz tools presentation for the JISC activity data synthesis project tomorrow, and an OU workshop around the iChart eSTeEM project – I rediscovered an app that I’d completely forgotten about: an online R server that supports the plotting of charts using the ggplot library (err, I think?!): http://www.yeroon.net/ggplot2/
Example of how to use http://www.yeroon.net/ggplot2/
By the by, I have started trying to get my head round R using RStudio, but the online ggplot2 environment masks the stats commands and just focusses on helping you create quick charts. I randomly uploaded one of my F1 timing data files from the British Grand Prix, had a random click around, and in 8(?) clicks – from uploading the file, to rendering the chart – I’d managed to create this:
What it shows is a scatterplot for each car showing the time on the current leader lap that the leader is ahead. When the plotted points drop from 100 or so seconds behind to just a few seconds behind, that car has been lapped.
What this chart shows (which I stumbled across just by playing with the environment) is a birds-eye view over the whole of the race, from each driver’s point of view. One thing I don’t make much use of is the colour dimension – or the size of each plotted point – but if tweak the input file to include the number of laps a car is behind the leader, their race position, the number of pitstops they’ve had, or their current tyre selection, I could easily view a couple more of these dimensions.
Where there’s a jump in the plotted points for a lap or two, if the step/break goes above the trend line (the gap to leader increases by 20s or so), the leader has lapped before the car. If the jump goes below the trend line (the gap to the leader has decreased), the leader has pitted before the car in question.
But that’s not really the point; what is the point is that here is a solution (and I think mirroring options are a possibility) for hosting within an institution an interactive chart generator. I also wonder to what extent it would be possible to extend the environment to detect single sign on credentials and allow a student to access a set of files related to a particular course, for example? Alternatively, it looks as if there is support for loading files in from Google Docs, so would it be possible to use this environment as a way of providing a graphing environment for data files stored (and maybe shared via a course) within a student’s Google Apps account?