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arXiv 1906.09665stat.MLcs.LGeess.SP
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复合扭曲高斯过程

Compositionally-Warped Gaussian Processes

Universidad de Chile(智利大学)

Gonzalo Rios, Felipe Tobar

摘要:

高斯过程(GP)是一个非参数的先验分布的时间,空间或其他高维索引集索引的功能。GP是一个灵活的模型,但其局限性是由其本身的性质:它只能模拟高斯边缘分布。为了对非高斯数据进行建模,可以通过非线性变换(或扭曲)来扭曲GP,如由扭曲的GP(WGP)和计算要求更高的替代方案(例如贝叶斯WGP和深度GP)执行的。然而,WGP需要一个数值近似的逆翘曲预测,这增加了计算复杂性在实践中。为了回避这个问题,我们构造了一类新的warpings组成的多个基本功能的组合物,其逆是已知的明确。然后,我们提出了组合翘曲GP(CWGP),一个非高斯生成模型,其表现力来自其深层的组合架构,其计算效率是由分析逆翘曲保证。使用合成和真实世界的数据集进行的实验验证证实,所提出的CWGP对翘曲的选择是鲁棒的,并且提供比WGP更准确的点预测、更好的训练模型和更短的计算时间。

英文摘要:

The Gaussian process (GP) is a nonparametric prior distribution over functions indexed by time, space, or other high-dimensional index set. The GP is a flexible model yet its limitation is given by its very nature: it can only model Gaussian marginal distributions. To model non-Gaussian data, a GP can be warped by a nonlinear transformation (or warping) as performed by warped GPs (WGPs) and more computationally-demanding alternatives such as Bayesian WGPs and deep GPs. However, the WGP requires a numerical approximation of the inverse warping for prediction, which increases the computational complexity in practice. To sidestep this issue, we construct a novel class of warpings consisting of compositions of multiple elementary functions, for which the inverse is known explicitly. We then propose the compositionally-warped GP (CWGP), a non-Gaussian generative model whose expressiveness follows from its deep compositional architecture, and its computational efficiency is guaranteed by the analytical inverse warping. Experimental validation using synthetic and real-world datasets confirms that the proposed CWGP is robust to the choice of warpings and provides more accurate point predictions, better trained models and shorter computation times than WGP.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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