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Fast Gaussian Process Posteriors with Product Trees
Proceedings of the 30th Conference on Uncertainty in Artificial Intelligence, PMLR R12:843-852, 2014.
Abstract
Gaussian processes (GP) are a powerful tool for nonparametric regression; unfortunately, calcu- lating the posterior variance in a standard GP model requires time O(n2) in the size of the training set. Previous work by Shen et al. (2006) used a k-d tree structure to approximate the pos- terior mean in certain GP models. We extend this approach to achieve efficient approximation of the posterior covariance using a tree clustering on pairs of training points, and demonstrate sig- nificant improvements in performance with neg- ligible loss of accuracy.