2018/02/06 by Phillips, Jeff M., Tai, Wai Ming · 3 citations
#Computational Geometry (cs.CG) #FOS: Computer and information sciences #Machine Learning (cs.LG) #Machine Learning (stat.ML)
paper · doi:10.48550/arxiv.1802.01751
We construct near-optimal coresets for kernel density estimates for points in ℝd when the kernel is positive definite. Specifically we show a polynomial time construction for a coreset of size O(√(d)/ε⋅ √(log 1/ε) ), and we show a near-matching lower bound of size Ω(min\√(d)/ε, 1/ε2\). When d≥ 1/ε2, it is known that the size of coreset can be O(1/ε2). The upper bound is a polynomial-in-(1/ε) improvement when d ∈ [3,1/ε2) and the lower bound is the first known lower bound to depend on d for this problem. Moreover, the upper bound restriction that the kernel is positive definite is significant in that it applies to a wide-variety of kernels, specifically those most important for machine learning. This includes kernels for information distances and the sinc kernel which can be negative.