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arXiv 1502.07685stat.MLstat.ME
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均值场变分Bayes的协方差阵和影响分数

Covariance Matrices and Influence Scores for Mean Field Variational Bayes

Ryan Giordano, Tamara Broderick

摘要:

平均场变分贝叶斯(MFVB)是一种流行的后验近似方法,由于其在大规模数据集上的快速运行。然而,众所周知,MFVB的一个主要缺点是它低估了模型变量的不确定性(有时严重),并且没有提供关于模型变量协方差的信息。我们为指数族开发了一种快速,通用的方法,该方法增强了MFVB,为模型变量提供准确的不确定性估计-无论是单个变量还是跨变量的一致性。指数族的MFVB定义了一个近似后验均值的不动点方程,我们的方法通过扰动这个不动点来得到协方差估计。受线性响应理论的启发,我们称我们的方法为线性响应变分贝叶斯(LRVB)。我们还展示了LRVB如何用于快速计算单个数据点对参数点估计的影响。我们通过学习模拟和真实数据的高斯混合模型来证明我们方法的准确性和可扩展性。

英文摘要:

Mean field variational Bayes (MFVB) is a popular posterior approximation method due to its fast runtime on large-scale data sets. However, it is well known that a major failing of MFVB is that it underestimates the uncertainty of model variables (sometimes severely) and provides no information about model variable covariance. We develop a fast, general methodology for exponential families that augments MFVB to deliver accurate uncertainty estimates for model variables -- both for individual variables and coherently across variables. MFVB for exponential families defines a fixed-point equation in the means of the approximating posterior, and our approach yields a covariance estimate by perturbing this fixed point. Inspired by linear response theory, we call our method linear response variational Bayes (LRVB). We also show how LRVB can be used to quickly calculate a measure of the influence of individual data points on parameter point estimates. We demonstrate the accuracy and scalability of our method by learning Gaussian mixture models for both simulated and real data.

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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