Abstract
Chow and Liu [2] has shown that learning trees that maximize likelihood score given data can be done in polynomial time. A generalization of directed trees are polytrees. However, Dasgupta [3] has proved that learning maximum likelihood polytrees from data (and even approximation of the optimal result with a constant ratio) is NPHard. Therefore, researchers have focused on learning maximum likelihood polytrees with a constant number of roots. Gaspers et al. [5] have presented such an algorithm with complexity O(mn 3k + 4) using matroid theory. We present a direct combinatorial algorithm with complexity O(mn 3k + 1).
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Safaei, J., Maňuch, J., Stacho, L. (2013). Learning Polytrees with Constant Number of Roots from Data. In: Cranefield, S., Nayak, A. (eds) AI 2013: Advances in Artificial Intelligence. AI 2013. Lecture Notes in Computer Science(), vol 8272. Springer, Cham. https://doi.org/10.1007/978-3-319-03680-9_45
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DOI: https://doi.org/10.1007/978-3-319-03680-9_45
Publisher Name: Springer, Cham
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