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arXiv 2103.03771math.STmath.COstat.TH
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贪婪的因果发现是几何的

Greedy Causal Discovery is Geometric

Svante Linusson, Petter Restadh, Liam Solus

摘要:

找到一个有向无圈图(DAG),最好的编码条件独立性语句观察到的数据是因果关系中的一个中心问题。在给定一组固定移动的情况下,将一个候选DAG绿变换成另一个候选DAG的算法已经特别成功,例如GES、GIES和MMHC算法。在2010年,Studenfeld,Hemmecke和Lindner引入了特征模集多面体,$\operatorname{CIM}_p$,其顶点对应于马尔可夫等价类,作为将因果发现转化为线性最优化问题的一种方法。我们表明,上述算法的移动包括在类的边缘$\operatorname{CIM}_p$和限制放在骨架上的候选DAG对应于面对的$\operatorname{CIM}_p$。因此,我们观察到,GES,GIES,和MMHC都有几何实现的贪婪边行走沿$\operatorname{CIM}_p$。此外,$\operatorname{CIM}_p$的识别边缘严格推广了这些算法的移动。利用这一概括,我们引入了一个贪婪的单纯型算法称为\emph{greedy CIM},和一个混合的变种,\emph{skeletal greedy CIM},优于目前的竞争对手之间的混合和基于约束的算法。

英文摘要:

Finding a directed acyclic graph (DAG) that best encodes the conditional independence statements observable from data is a central question within causality. Algorithms that greedily transform one candidate DAG into another given a fixed set of moves have been particularly successful, for example the GES, GIES, and MMHC algorithms. In 2010, Studený, Hemmecke and Lindner introduced the characteristic imset polytope, $\operatorname{CIM}_p$, whose vertices correspond to Markov equivalence classes, as a way of transforming causal discovery into a linear optimization problem. We show that the moves of the aforementioned algorithms are included within classes of edges of $\operatorname{CIM}_p$ and that restrictions placed on the skeleton of the candidate DAGs correspond to faces of $\operatorname{CIM}_p$. Thus, we observe that GES, GIES, and MMHC all have geometric realizations as greedy edge-walks along $\operatorname{CIM}_p$. Furthermore, the identified edges of $\operatorname{CIM}_p$ strictly generalize the moves of these algorithms. Exploiting this generalization, we introduce a greedy simplex-type algorithm called \emph{greedy CIM}, and a hybrid variant, \emph{skeletal greedy CIM}, that outperforms current competitors among hybrid and constraint-based algorithms.

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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