If you want to follow along (go on) then you should head over to Neil’s site, download the excel file and take a look at the “how to” guide on the same page. Existing R users are already likely to be shuddering at all the manual manipulation required.
For the first attempt, I followed Neil’s approach pretty closely, resulting in a lot of code to sort and group, although ggplot2 made the actual plotting much simpler. I shared my very first attempt ( produce with barely any ggplot2 code) which was quite good, but there were a few issues – the ins/ outs being coloured blue instead of grey, and overplotting of several points.
Click through for code and explanation. H/T R-Bloggers