Multi-Swap $k$-Means++

Fuente: arXiv
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Autori principali: Beretta, Lorenzo, Cohen-Addad, Vincent, Lattanzi, Silvio, Parotsidis, Nikos
Natura: Preprint
Pubblicazione: 2023
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author Beretta, Lorenzo
Cohen-Addad, Vincent
Lattanzi, Silvio
Parotsidis, Nikos
author_facet Beretta, Lorenzo
Cohen-Addad, Vincent
Lattanzi, Silvio
Parotsidis, Nikos
contents The $k$-means++ algorithm of Arthur and Vassilvitskii (SODA 2007) is often the practitioners' choice algorithm for optimizing the popular $k$-means clustering objective and is known to give an $O(\log k)$-approximation in expectation. To obtain higher quality solutions, Lattanzi and Sohler (ICML 2019) proposed augmenting $k$-means++ with $O(k \log \log k)$ local search steps obtained through the $k$-means++ sampling distribution to yield a $c$-approximation to the $k$-means clustering problem, where $c$ is a large absolute constant. Here we generalize and extend their local search algorithm by considering larger and more sophisticated local search neighborhoods hence allowing to swap multiple centers at the same time. Our algorithm achieves a $9 + \varepsilon$ approximation ratio, which is the best possible for local search. Importantly we show that our approach yields substantial practical improvements, we show significant quality improvements over the approach of Lattanzi and Sohler (ICML 2019) on several datasets.
format Preprint
id arxiv_https___arxiv_org_abs_2309_16384
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Multi-Swap $k$-Means++
Beretta, Lorenzo
Cohen-Addad, Vincent
Lattanzi, Silvio
Parotsidis, Nikos
Computational Geometry
Machine Learning
The $k$-means++ algorithm of Arthur and Vassilvitskii (SODA 2007) is often the practitioners' choice algorithm for optimizing the popular $k$-means clustering objective and is known to give an $O(\log k)$-approximation in expectation. To obtain higher quality solutions, Lattanzi and Sohler (ICML 2019) proposed augmenting $k$-means++ with $O(k \log \log k)$ local search steps obtained through the $k$-means++ sampling distribution to yield a $c$-approximation to the $k$-means clustering problem, where $c$ is a large absolute constant. Here we generalize and extend their local search algorithm by considering larger and more sophisticated local search neighborhoods hence allowing to swap multiple centers at the same time. Our algorithm achieves a $9 + \varepsilon$ approximation ratio, which is the best possible for local search. Importantly we show that our approach yields substantial practical improvements, we show significant quality improvements over the approach of Lattanzi and Sohler (ICML 2019) on several datasets.
title Multi-Swap $k$-Means++
topic Computational Geometry
Machine Learning
url https://arxiv.org/abs/2309.16384