Fig. 6.

Clustering of positions (Xs) is done by traversing up the snarl tree and progressively agglomerating clusters. Positions are colored by the final clusters. (a) Each position starts out in a separate cluster on a node. Each cluster is annotated with its boundary distances: the minimum distances from any of its positions to the ends of the structure it is on. (b) For each snarl on the lowest level of the snarl tree, the clusters on the snarl’s children are agglomerated into new clusters on the snarl. The boundary distances are extended to the ends of the snarl. (c) For each chain on the next level of the snarl tree, the clusters on the chain’s snarls are agglomerated and the boundary distances are updated to reach the ends of the chain. This process is repeated on each level of the snarl tree up to the root