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arXiv · 2004.04523

k-Nearest Neighbour Classifiers: 2nd Edition (with Python examples)

Padraig Cunningham·Sarah Jane Delany
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Abstract

Perhaps the most straightforward classifier in the arsenal or machine learning techniques is the Nearest Neighbour Classifier -- classification is achieved by identifying the nearest neighbours to a query example and using those neighbours to determine the class of the query. This approach to classification is of particular importance because issues of poor run-time performance is not such a problem these days with the computational power that is available. This paper presents an overview of techniques for Nearest Neighbour classification focusing on; mechanisms for assessing similarity (distance), computational issues in identifying nearest neighbours and mechanisms for reducing the dimension of the data. This paper is the second edition of a paper previously published as a technical report. Sections on similarity measures for time-series, retrieval speed-up and intrinsic dimensionality have been added. An Appendix is included providing access to Python code for the key methods.

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Padraig Cunningham, Sarah Jane Delany. 2020-04-09. k-Nearest Neighbour Classifiers: 2nd Edition (with Python examples). https://doi.org/10.1145/3459665

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