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arXiv 1506.04321stat.ME
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椭圆图解建模

Elliptical graphical modelling

Daniel Vogel, Roland Fried

摘要:

我们提出了基于条件不相关性的椭圆图模型作为高斯图模型的推广,通过使总体分布是椭圆而不是正态分布,允许拟合具有任意重尾的数据。我们研究了一类比例仿射同变散布估计,并展示了它们如何用于执行椭圆图形建模,从而产生一类新的偏相关估计和经典偏差检验的类似物。本文给出了无约束和可分解模型下偏方差估计的渐近方差的一般表达式,并证明了伪偏差检验统计量的渐近卡方逼近。我们的方法的可行性证明了模拟研究,使用,除其他外,泰勒的散射估计,这是分布内的椭圆模型。我们的方法提供了高斯图形建模的鲁棒性。后者是基于似然性的,并且已知对模型错误指定和离群观测非常敏感。

英文摘要:

We propose elliptical graphical models based on conditional uncorrelatedness as a general- ization of Gaussian graphical models by letting the population distribution be elliptical instead of normal, allowing the fitting of data with arbitrarily heavy tails. We study the class of propor- tionally affine equivariant scatter estimators and show how they can be used to perform elliptical graphical modelling, leading to a new class of partial correlation estimators and analogues of the classical deviance test. General expressions for the asymptotic variance of partial correla- tion estimators, unconstrained and under decomposable models, are given, and the asymptotic chi square approximation of the pseudo-deviance test statistic is proved. The feasibility of our approach is demonstrated by a simulation study, using, among others, Tyler's scatter estimator, which is distribution-free within the elliptical model. Our approach provides a robustification of Gaussian graphical modelling. The latter is likelihood-based and known to be very sensitive to model misspecification and outlying observations.

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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