Marginal parameterizations of discrete models defined by a set of conditional independencies
Marginal parameterizations of discrete models defined by a set of conditional independencies
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DOI：
10.1016/j.jmva.2010.07.001
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发表时间：
2010-11-01
影响因子：
1.6
通讯作者：
Marchetti, G. M.
中科院分区：
文献类型：
--
作者：
Forcina, A.;Lupparelli, M.;Marchetti, G. M.
众所周知，离散变量的条件独立性声明等价于将一组合适的对数线性相互作用约束为零。在本文中，我们表明，这也是等价于零约束适当的边际对数线性相互作用，可以制定一类光滑的边际对数线性模型。这个结果允许更多的灵活性比已知的，直到现在在结合几个条件独立到一个光滑的边际模型。这个结果是一个程序，可以搜索这样的边际参数化的基础上，所以，如果存在，模型是光滑的。(c)2010年爱思唯尔公司All rights reserved.
It is well-known that a conditional independence statement for discrete variables is equivalent to constraining to zero a suitable set of log-linear interactions. In this paper we show that this is also equivalent to zero constraints on suitable sets of marginal log-linear interactions, that can be formulated within a class of smooth marginal log-linear models. This result allows much more flexibility than known until now in combining several conditional independencies into a smooth marginal model. This result is the basis for a procedure that can search for such a marginal parameterization, so that, if one exists, the model is smooth. (c) 2010 Elsevier Inc. All rights reserved.