title: how to create a subway map visualisation of my data
body: <p>Found the nice figure below in a paper (<a href="http://www.ncbi.nlm.nih.gov/pubmed/25626705" rel="nofollow noreferrer">http://www.ncbi.nlm.nih.gov/pubmed/25626705</a>). It visualises the workflows of different laboratories and illustrates nicely where they diverge. Could see this being useful for many other datasets.</p>
  
  <p>Is there a tool that facilitates creation of these kinds of maps from a set of data (i.e. avoids me to have to draw this in a drawing app from scratch)?</p>
  
  <p>Can I do something like this in ggplot2?</p>
  
  <p><a href="https://i.stack.imgur.com/kB6Eu.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kB6Eu.jpg" alt="subway map"></a></p>