Date of this Version
Proceedings of the 23rd International Conference on Machine Learning
We present a tree data structure for fast nearest neighbor operations in general n-point metric spaces (where the data set consists of n points). The data structure requires O(n) space regardless of the metric's structure yet maintains all performance properties of a navigating net (Krauthgamer & Lee, 2004b). If the point set has a bounded expansion constant c, which is a measure of the intrinsic dimensionality, as defined in (Karger & Ruhl, 2002), the cover tree data structure can be constructed in O (c6n log n) time. Furthermore, nearest neighbor queries require time only logarithmic in n, in particular O (c12 log n) time. Our experimental results show speedups over the brute force search varying between one and several orders of magnitude on natural machine learning datasets.
Beygelzimer, A., Kakade, S. M., & Langford, J. (2006). Cover Trees for Nearest Neighbor. Proceedings of the 23rd International Conference on Machine Learning, 97-104. Retrieved from https://repository.upenn.edu/statistics_papers/121
Date Posted: 27 November 2017