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Accelerating Exact k-means Algorithms with Geometric Reasoning (1999)

Dan Pelleg, Andrew Moore

Tags

Astrostatistics, Cached Sufficient Statistics, Clustering, Efficient Statistical Algorithms, Kd-trees and Ball-trees, Mixture Models, Statistical Data Mining for Astrophysics

Abstract

A K-means tutorial.
We present new algorithms for the k-means clustering problem. They use the kd-tree data structure to reduce the large number of nearest-neighbor queries issued by the traditional algorithm. Sufficient statistics are stored in the nodes of the kd-tree. Then, an analysis of the geometry of the current cluster centers results in great reduction of the work needed to update the centers. Our algorithms behave exactly as the traditional k-means algorithm. Proofs of correctness are included. The kd-tree can also be used to initialize the k-means starting centers efficiently. Our algorithms can be easily extended to provide fast ways of computing the error of a given cluster assignment, regardless of the method in which those clusters were obtained. We also show how to use them in a setting which allows approximate clustering results, with the benefit of running faster. We have implemented and tested our algorithms on both real and simulated data. Results show a speedup factor of up to 170 on real astrophysical data, and superiority over the naive algorithm on simulated data in up to 5 dimensions. Our algorithms scale well with respect to the number of points and number of centers, allowing for clustering with tens of thousands of centers.

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Approximate BibTeX Entry

@inproceedings{pelleg-accelerating,
    Month = {aug},
    Year = {1999},
    Pages = {277--281},
    Publisher = {AAAI Press},
    Booktitle = {Proceedings of the Fifth International Conference on Knowledge Discovery in Databases},
    Editor = {Surajit Chaudhuri and David Madigan},
    Author = { Dan Pelleg, Andrew Moore },
    Title = {Accelerating Exact k-means Algorithms with Geometric Reasoning}
}

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