$(1+\varepsilon)$-ANN Data Structure for Curves via Subspaces of Bounded Doubling Dimension

Fuente: arXiv
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Main Authors: Conradi, Jacobus, Driemel, Anne, Kolbe, Benedikt
Format: Preprint
Published: 2023
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author Conradi, Jacobus
Driemel, Anne
Kolbe, Benedikt
author_facet Conradi, Jacobus
Driemel, Anne
Kolbe, Benedikt
contents We consider the $(1+\varepsilon)$-Approximate Nearest Neighbour (ANN) Problem for polygonal curves in $d$-dimensional space under the Fréchet distance and ask to what extent known data structures for doubling spaces can be applied to this problem. Initially, this approach does not seem viable, since the doubling dimension of the target space is known to be unbounded -- even for well-behaved polygonal curves of constant complexity in one dimension. In order to overcome this, we identify a subspace of curves which has bounded doubling dimension and small Gromov-Hausdorff distance to the target space. We then apply state-of-the-art techniques for doubling spaces and show how to obtain a data structure for the $(1+\varepsilon)$-ANN problem for any set of parametrized polygonal curves. The expected preprocessing time needed to construct the data-structure is $F(d,k,S,\varepsilon)n\log n$ and the space used is $F(d,k,S,\varepsilon)n$, with a query time of $F(d,k,S,\varepsilon)\log n + F(d,k,S,\varepsilon)^{-\log(\varepsilon)}$, where $F(d,k,S,\varepsilon)=O\left(2^{O(d)}kΦ(S)\varepsilon^{-1}\right)^k$ and $Φ(S)$ denotes the spread of the set of vertices and edges of the curves in $S$. We extend these results to the realistic class of $c$-packed curves and show improved bounds for small values of $c$.
format Preprint
id arxiv_https___arxiv_org_abs_2307_08521
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle $(1+\varepsilon)$-ANN Data Structure for Curves via Subspaces of Bounded Doubling Dimension
Conradi, Jacobus
Driemel, Anne
Kolbe, Benedikt
Computational Geometry
68W25
F.2; E.1
We consider the $(1+\varepsilon)$-Approximate Nearest Neighbour (ANN) Problem for polygonal curves in $d$-dimensional space under the Fréchet distance and ask to what extent known data structures for doubling spaces can be applied to this problem. Initially, this approach does not seem viable, since the doubling dimension of the target space is known to be unbounded -- even for well-behaved polygonal curves of constant complexity in one dimension. In order to overcome this, we identify a subspace of curves which has bounded doubling dimension and small Gromov-Hausdorff distance to the target space. We then apply state-of-the-art techniques for doubling spaces and show how to obtain a data structure for the $(1+\varepsilon)$-ANN problem for any set of parametrized polygonal curves. The expected preprocessing time needed to construct the data-structure is $F(d,k,S,\varepsilon)n\log n$ and the space used is $F(d,k,S,\varepsilon)n$, with a query time of $F(d,k,S,\varepsilon)\log n + F(d,k,S,\varepsilon)^{-\log(\varepsilon)}$, where $F(d,k,S,\varepsilon)=O\left(2^{O(d)}kΦ(S)\varepsilon^{-1}\right)^k$ and $Φ(S)$ denotes the spread of the set of vertices and edges of the curves in $S$. We extend these results to the realistic class of $c$-packed curves and show improved bounds for small values of $c$.
title $(1+\varepsilon)$-ANN Data Structure for Curves via Subspaces of Bounded Doubling Dimension
topic Computational Geometry
68W25
F.2; E.1
url https://arxiv.org/abs/2307.08521