A new near-linear time algorithm for k-nearest neighbor search using a compressed cover tree



Elkin, Yury and Kurlin, Vitaliy ORCID: 0000-0001-5328-5351
(2021) A new near-linear time algorithm for k-nearest neighbor search using a compressed cover tree. [Preprint]

[img] Text
2111.15478v2.pdf - Submitted version

Download (826kB) | Preview

Abstract

Given a reference set $R$ of $n$ points and a query set $Q$ of $m$ points in a metric space, this paper studies an important problem of finding $k$-nearest neighbors of every point $q \in Q$ in the set $R$ in a near-linear time. In the paper at ICML 2006, Beygelzimer, Kakade, and Langford introduced a cover tree on $R$ and attempted to prove that this tree can be built in $O(n\log n)$ time while the nearest neighbor search can be done in $O(n\log m)$ time with a hidden dimensionality factor. This paper fills a substantial gap in the past proofs of time complexity by defining a simpler compressed cover tree on the reference set $R$. The first new algorithm constructs a compressed cover tree in $O(n \log n)$ time. The second new algorithm finds all $k$-nearest neighbors of all points from $Q$ using a compressed cover tree in time $O(m(k+\log n)\log k)$ with a hidden dimensionality factor depending on point distributions of the given sets $R,Q$ but not on their sizes.

Item Type: Preprint
Additional Information: Accepted to ICML 2023
Uncontrolled Keywords: cs.CG, cs.CG, cs.DS
Divisions: Faculty of Science and Engineering > School of Electrical Engineering, Electronics and Computer Science
Depositing User: Symplectic Admin
Date Deposited: 24 Jan 2022 08:23
Last Modified: 15 Mar 2024 12:38
DOI: 10.48550/arxiv.2111.15478
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3147440