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arXiv 2004.01927stat.ME
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多变量深度统计的概念选择

Choosing among notions of multivariate depth statistics

Karl Mosler, Pavlo Mozharovskyi

摘要:

经典的多元统计方法是根据数据的均值和协方差阵,通过点与均值的马氏距离来度量点的离群性。多变量深度函数是这样一种函数,给定d空间中的一个点和一个分布,通过0和1之间的一个数字来测量中心性,同时满足关于不变性,单调性,凸性和连续性的某些假设。因此,在文献中已经提出了许多多变量深度的概念,其中一些对于极端离群数据也是鲁棒的。偏离经典的马哈拉诺比斯距离并非没有代价。在不变性、鲁棒性和计算可行性之间存在折衷。在过去的几年中,高效的精确算法以及近似的已经构建,并提供在R-包。因此,在实际应用中,由于计算限制,深度统计量的选择不再局限于一个或两个概念;而往往是更多的概念是可行的,其中研究人员必须决定。文章讨论了这种选择的理论和实践方面,包括不变性和唯一性,鲁棒性和计算的可行性。比较了精确算法的复杂度和速度。近似方法,如随机Tukey深度的精度进行了讨论,以及应用到大型和高维数据。扩展到本地和功能的深度和回归深度的连接,很快解决。

英文摘要:

Classical multivariate statistics measures the outlyingness of a point by its Mahalanobis distance from the mean, which is based on the mean and the covariance matrix of the data. A multivariate depth function is a function which, given a point and a distribution in d-space, measures centrality by a number between 0 and 1, while satisfying certain postulates regarding invariance, monotonicity, convexity and continuity. Accordingly, numerous notions of multivariate depth have been proposed in the literature, some of which are also robust against extremely outlying data. The departure from classical Mahalanobis distance does not come without cost. There is a trade-off between invariance, robustness and computational feasibility. In the last few years, efficient exact algorithms as well as approximate ones have been constructed and made available in R-packages. Consequently, in practical applications the choice of a depth statistic is no more restricted to one or two notions due to computational limits; rather often more notions are feasible, among which the researcher has to decide. The article debates theoretical and practical aspects of this choice, including invariance and uniqueness, robustness and computational feasibility. Complexity and speed of exact algorithms are compared. The accuracy of approximate approaches like the random Tukey depth is discussed as well as the application to large and high-dimensional data. Extensions to local and functional depths and connections to regression depth are shortly addressed.

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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