,
Marc van Kreveld
,
Frank Staals
Creative Commons Attribution 4.0 International license
Let R ∪ B be a set of n points in R², and let k ∈ 1..n. Our goal is to compute a line that "best" separates the "red" points R from the "blue" points B with at most k outliers. We present an efficient semi-online dynamic data structure that can maintain whether such a separator exists ("semi-online" meaning that when a point is inserted, we know when it will be deleted). Furthermore, we present efficient exact and approximation algorithms that compute a linear separator that is guaranteed to misclassify at most k, points and minimizes the distance to the farthest outlier. Our exact algorithm runs in O(nk + n log n) time, and our (1+ε)-approximation algorithm runs in O(ε^(-1/2)((n + k²) log n)) time. Based on our (1+ε)-approximation algorithm we then also obtain a semi-online data structure to maintain such a separator efficiently.
@InProceedings{glazenburg_et_al:LIPIcs.ISAAC.2024.34,
author = {Glazenburg, Erwin and van Kreveld, Marc and Staals, Frank},
title = {{Robust Classification of Dynamic Bichromatic Point Sets in R²}},
booktitle = {35th International Symposium on Algorithms and Computation (ISAAC 2024)},
pages = {34:1--34:14},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-354-6},
ISSN = {1868-8969},
year = {2024},
volume = {322},
editor = {Mestre, Juli\'{a}n and Wirth, Anthony},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ISAAC.2024.34},
URN = {urn:nbn:de:0030-drops-221615},
doi = {10.4230/LIPIcs.ISAAC.2024.34},
annote = {Keywords: classification, duality, data structures, dynamic, linear programming}
}