Fast implementations (in O(n log(n))) of two univariate hierarchical clustering methods (1 dimensional Ward hierarchical clustering and l1 clusterpath). Resulting hierarchies are exported as hclust object.
devtools::install_github("jchiquet/univarclust").Chiquet J, Gutierrez P, Rigaill G: Fast tree inference with weighted fusion penalties, Journal of Computational and Graphical Statistics 205–216, 2017. PDF version
Toby Hocking, Jean-Philippe Vert, Francis Bach, and Armand Joulin. Clusterpath: an Algorithm for Clustering using Convex Fusion Penalties, Proceedings of the 28th International Conference on Machine Learning (ICML-11), 2011.