Create stub .R files
Create stub for a common data loading script.
Implement loading the relevent data.

For now keep the result in a separate file.
Draw the first plot correctly to the screen.
Draw the second plot correctly to the screen.
Draw the third plot correctly to the screen.
Draw the fourth plot correctly to the screen.
Chande the scripts so they draw to PNG files.
Fix typos.
Duplicate the data loading code to each script.
Load packages in each script.

So they can run on their own.
Add the resulting plots to the repo.

These were produced by running
Rscript plot1.R
Rscript plot2.R
Rscript plot3.R
Rscript plot4.R