I've been working on getting this on my Raspberry Pi (Model 3 B+) for a couple of days.  Originally I had some problems with the directed graphs showing properly.  The edge tags, just said "Edge Tag" rather than what was shown in the article.  I thought that maybe I was typing things incorrectly so I did a copy and paste directly from the article.  I continued to have the same problem.  
The final project that I did for my MS in Mathematics dealt with SER models for two regions with different R naughts (in Matlab), so the graphs were of more interest to me.  I continued to copy and paste all the code.  In the section entitled "Generating equations from graph specifications" it would not interpret the code that starts "lsEdges = "and I could not figure out how to do the directed graphs with edges from the documentation given in the "Learning & Support" section.
When I got to the end with the graphs, again doing a copy and paste on the code from the article, I just got a flat line.  This isn't really what I was hoping for.  
Am I having problems because I'm trying to do this on the Raspberry Pi?  I made sure that I had the latest version of Mathematica before I started.  I'm relatively new to Mathematica and would like to continue to use it.  Given what I want to do (graphs) is there another route I should be taking?
Thank you
Charles Gerheim