Triadic Closure 2D — Force-Directed Network Growth

This 2D companion to the 3D Holme–Kim triadic-closure simulator keeps the same growth mathematics — each arriving node attaches with a first random link, then with tunable probability p either closes a friend-of-a-friend triangle or attaches randomly again — but replaces the orbiting 3D camera with a genuinely planar mechanic: an independently-computed 2D spring-repulsion force layout that settles the growing graph directly in the plane, contained by a soft boundary force rather than an auto-fitting camera. Two live plots track statistics that have no counterpart in the 3D version: the running history of the average clustering coefficient against the Erdős–Rényi random-graph baseline, and the live degree distribution across all nodes. An exact graph diameter, recomputed by breadth-first search every time the network changes, exposes the "small-world" signature — short paths between any two people even as local clustering climbs — that this same triadic-closure rule produces in real friendship and collaboration networks.