@article{JSSv102c01, title={Monotone Regression: A Simple and Fast O(n) PAVA Implementation}, volume={102}, url={https://www.jstatsoft.org/index.php/jss/article/view/v102c01}, doi={10.18637/jss.v102.c01}, abstract={<p>Efficient coding and improvements in the execution order of the up-and-down-blocks algorithm for monotone or isotonic regression leads to a significant increase in speed as well as a short and simple O(n) implementation. Algorithms that use monotone regression as a subroutine, e.g., unimodal or bivariate monotone regression, also benefit from the acceleration. A substantive comparison with and characterization of currently available implementations provides an extensive overview of up-and-down-blocks implementations for the pool-adjacent-violators algorithm for simple linear ordered monotone regression.</p>}, number={1}, journal={Journal of Statistical Software, Code Snippets}, author={Busing, Frank M. T. A.}, year={2022}, pages={1–25} }