20. Cybertrees: Tree-Shaped Overview Maps
This chapter introduces two algorithms CREATE-LOCAL-TREES and CREATE-GLOBAL-TREE, based on Kruskal's minimum spanning tree algorithm [Cor90]. Kruskal's algorithm builds a m.s.t by growing a forest and adds the unconnected edge with the heighest weight to the tree until all nodes are connected. By omitting tree-connecting links in Kruskal's algorithm, we get a clustering in local trees; inclusion of the tree-connecting links results in the global tree.