  We present an accelerated algorithm for hierarchical density based
clustering. Our new algorithm improves upon HDBSCAN*, which itself provided a
significant qualitative improvement over the popular DBSCAN algorithm. The
accelerated HDBSCAN* algorithm provides comparable performance to DBSCAN, while
supporting variable density clusters, and eliminating the need for the
difficult to tune distance scale parameter. This makes accelerated HDBSCAN* the
default choice for density based clustering.
  Library available at: https://github.com/scikit-learn-contrib/hdbscan
