arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2008.09848cs.LGstat.ML
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多输出高斯过程的快速逼近

Fast Approximate Multi-output Gaussian Processes

University of Waterloo(滑铁卢大学);Monash University(莫纳什大学)

Vladimir Joukov, Dana Kulić

摘要:

高斯过程回归模型是一种有吸引力的机器学习方法,因为它们从样本数据中学习表达性的非线性模型,具有最小的参数调整,并估计未知点的均值和协方差。然而,随着训练样本数量的指数计算复杂性增长一直是一个长期存在的挑战。在训练过程中,必须在每次迭代时计算和求逆$N \times N$核矩阵。回归需要计算$m \times N$内核,其中$N$和$m$分别是训练点和测试点的数量。在这项工作中,我们将展示如何使用特征值和函数近似协方差核,从而导致近似高斯过程,并显着降低训练和回归复杂性。用所提出的方法进行训练只需要计算$N \times n$特征函数矩阵和$n \times n$逆,其中$n$是所选择的特征值数目。此外,回归现在只需要一个$m \times n$矩阵。最后,在特殊情况下,超参数优化与训练样本的数目完全无关。该方法可以对多个输出进行回归,估计任意阶回归量的导数,并学习它们之间的相关性。在仿真示例中演示了计算复杂性降低、回归功能和多输出相关学习。

英文摘要:

Gaussian processes regression models are an appealing machine learning method as they learn expressive non-linear models from exemplar data with minimal parameter tuning and estimate both the mean and covariance of unseen points. However, exponential computational complexity growth with the number of training samples has been a long standing challenge. During training, one has to compute and invert an $N \times N$ kernel matrix at every iteration. Regression requires computation of an $m \times N$ kernel where $N$ and $m$ are the number of training and test points respectively. In this work we show how approximating the covariance kernel using eigenvalues and functions leads to an approximate Gaussian process with significant reduction in training and regression complexity. Training with the proposed approach requires computing only a $N \times n$ eigenfunction matrix and a $n \times n$ inverse where $n$ is a selected number of eigenvalues. Furthermore, regression now only requires an $m \times n$ matrix. Finally, in a special case the hyperparameter optimization is completely independent form the number of training samples. The proposed method can regress over multiple outputs, estimate the derivative of the regressor of any order, and learn the correlations between them. The computational complexity reduction, regression capabilities, and multioutput correlation learning are demonstrated in simulation examples.

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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