##graph-layoutgraph-layout

reingold-tilford in o(n), the polar-coordinate variant, hyperbolic focus+context, and squarified treemaps.

cycle removal, layer assignment, crossing reduction, coordinate assignment.

the quadtree approximation that turned force-directed from o(n²) to o(n log n), and the coarsening trick that scales it to a million nodes.

the spring-and-charge model, the fruchterman-reingold cooling schedule, and why two runs can give two different layouts.

what graph layout is, why it's hard, and the seven families that solve it.