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arXiv 0901.0026stat.ML
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离散指数族的几何及其在指数随机图模型中的应用

On the Geometry of Discrete Exponential Families with Application to Exponential Random Graph Models

Stephen E. Fienberg, Alessandro Rinaldo, Yi Zhou

摘要:

对用于分析网络数据的统计模型的兴趣激增,并且对指数随机图(ERG)模型类的兴趣相当大,特别是与计算最大似然估计的困难有关。与这些困难相关的问题涉及到离散指数族的更广泛的结构。本文分两部分重新审视这一问题。首先研究了$k$维指数分布族在离散基测度和多面体凸支撑$\mathrm{P}$下的闭包。我们表明,正常风扇的$\mathrm{P}$是一个几何对象,在推导相应的扩展指数族的统计和几何性质中起着根本性的作用。我们讨论了它的相关性极大似然估计,无论是从理论和计算的角度来看。其次,我们将我们的结果应用到ERG模型的分析。特别是,通过一个详细的例子,我们提供了一些特性的ERG模型,特别是某些行为的ERG模型被称为退化。

英文摘要:

There has been an explosion of interest in statistical models for analyzing network data, and considerable interest in the class of exponential random graph (ERG) models, especially in connection with difficulties in computing maximum likelihood estimates. The issues associated with these difficulties relate to the broader structure of discrete exponential families. This paper re-examines the issues in two parts. First we consider the closure of $k$-dimensional exponential families of distribution with discrete base measure and polyhedral convex support $\mathrm{P}$. We show that the normal fan of $\mathrm{P}$ is a geometric object that plays a fundamental role in deriving the statistical and geometric properties of the corresponding extended exponential families. We discuss its relevance to maximum likelihood estimation, both from a theoretical and computational standpoint. Second, we apply our results to the analysis of ERG models. In particular, by means of a detailed example, we provide some characterization of the properties of ERG models, and, in particular, of certain behaviors of ERG models known as degeneracy.

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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