Locality-Sensitive Bucketing Functions for the Edit Distance

Ke Chen, Mingfu Shao

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Many bioinformatics applications involve bucketing a set of sequences where each sequence is allowed to be assigned into multiple buckets. To achieve both high sensitivity and precision, bucketing methods are desired to assign similar sequences into the same bucket while assigning dissimilar sequences into distinct buckets. Existing k-mer-based bucketing methods have been efficient in processing sequencing data with low error rate, but encounter much reduced sensitivity on data with high error rate. Locality-sensitive hashing (LSH) schemes are able to mitigate this issue through tolerating the edits in similar sequences, but state-of-the-art methods still have large gaps. Here we generalize the LSH function by allowing it to hash one sequence into multiple buckets. Formally, a bucketing function, which maps a sequence (of fixed length) into a subset of buckets, is defined to be (d1, d2)-sensitive if any two sequences within an edit distance of d1 are mapped into at least one shared bucket, and any two sequences with distance at least d2 are mapped into disjoint subsets of buckets. We construct locality-sensitive bucketing (LSB) functions with a variety of values of (d1, d2) and analyze their efficiency with respect to the total number of buckets needed as well as the number of buckets that a specific sequence is mapped to. We also prove lower bounds of these two parameters in different settings and show that some of our constructed LSB functions are optimal. These results provide theoretical foundations for their practical use in analyzing sequences with high error rate while also providing insights for the hardness of designing ungapped LSH functions.

Original languageEnglish (US)
Title of host publication22nd International Workshop on Algorithms in Bioinformatics, WABI 2022
EditorsChristina Boucher, Sven Rahmann
PublisherSchloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing
ISBN (Electronic)9783959772433
StatePublished - Sep 1 2022
Event22nd International Workshop on Algorithms in Bioinformatics, WABI 2022 - Potsdam, Germany
Duration: Sep 5 2022Sep 7 2022

Publication series

NameLeibniz International Proceedings in Informatics, LIPIcs
ISSN (Print)1868-8969


Conference22nd International Workshop on Algorithms in Bioinformatics, WABI 2022

All Science Journal Classification (ASJC) codes

  • Software


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