An attempt to replicate Mike's General Update Pattern, III with a pack layout (bubble chart). The update has four parts: (1) Join, (2) Exit, (3) Update, (4) Enter.
See also: Force Update Pattern, Voronoi Update Pattern II, Voronoi Update Pattern, and Modifying a Force Layout
forked from HarryStevens's block: Bubble Update Pattern
https://d3js.org/d3.v4.min.js