`scipy.cluster.hierarchy._optimal_leaf_ordering:optimal_leaf_ordering`

Signature

def optimal_leaf_ordering(Z, D)

Compute the optimal leaf order for Z (according to D) and return an optimally sorted Z.

We start by sorting and relabelling Z and D according to the current leaf order in Z.

This is because when everything is sorted each cluster (including singletons) can be defined by its range over (0...n_points).

This is used extensively to loop efficiently over the various arrays in the algorithm.