Article

Computing Posterior Probabilities of Structural Features in Bayesian Networks

05/2012;
Source: arXiv

ABSTRACT We study the problem of learning Bayesian network structures from data.
Koivisto and Sood (2004) and Koivisto (2006) presented algorithms that can
compute the exact marginal posterior probability of a subnetwork, e.g., a
single edge, in O(n2n) time and the posterior probabilities for all n(n-1)
potential edges in O(n2n) total time, assuming that the number of parents per
node or the indegree is bounded by a constant. One main drawback of their
algorithms is the requirement of a special structure prior that is non uniform
and does not respect Markov equivalence. In this paper, we develop an algorithm
that can compute the exact posterior probability of a subnetwork in O(3n) time
and the posterior probabilities for all n(n-1) potential edges in O(n3n) total
time. Our algorithm also assumes a bounded indegree but allows general
structure priors. We demonstrate the applicability of the algorithm on several
data sets with up to 20 variables.

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