Create plotter examples for these:

  verticalfill.py
  function.py

Do more examples from:
  
   ploticus website:
     http://ploticus.sourceforge.net/doc/welcome.html

   R graphs website:
     http://www.r-graph-gallery.com/all-graphs/

PDF driver?
  https://brendanzagaeski.appspot.com/0005.html
  http://wwwimages.adobe.com/content/dam/Adobe/en/devnet/pdf/pdfs/pdf_reference_1-7.pdf
  https://blog.idrsolutions.com/2013/01/understanding-the-pdf-file-format-overview/