Simon’s version of Daniel Shiffman’s Minimum Spanning Tree tutorial: Simon translated it from JavaScript into Processing (Java), “a much more complex project than the circles with no overlap!”

A minimum spanning tree or minimum weight spanning tree is a subset of the edges of a connected undirected graph that connects all the vertices together, without any cycles and with the minimum possible total edge weight. Simon said it resembled the Traveling Salesperson problem, except that the spanning tree can have “loose ends”: