This module implement building blocks used a black box in coreset constructions.
The algorithm computes an (alfa, beta) k-median approximation and is used as input
to coreset computations.
This module provides a simple user interface for clustering data via a coreset.
The data must be accessed via an iterator, see makeiter.
It chains the bmor,coreset. Then the coreset is clustered with kmedoid algorithms and ends with a pass dispatching all data
to their nearest coreset clustering center, recomputing global
cost and storing membership