A scatter plot of the PL xG data with axes and a button.

Help from: https://d3-graph-gallery.com/graph/line_select.html and https://www.w3schools.com/howto/howto_js_dropdown.asp and https://www.freecodecamp.org/news/how-to-build-a-dropdown-menu-with-javascript/ and https://alvarotrigo.com/blog/drop-down-menu-javascript/