2015/12/05 by Pengyu Wang, Phil Blunsom, Wang, Pengyu +1
Mathematics · #FOS: Computer and information sciences #Machine Learning (stat.ML) #stat.ML
paper · pdf · doi:10.48550/arxiv.1512.01665
NIPS Workshop on Time Series, 2015
arxiv created 2015/12/05 · arxiv updated 2015/12/08
Stochastic variational inference for collapsed models has recently been successfully applied to large scale topic modelling. In this paper, we propose a stochastic collapsed variational inference algorithm for hidden Markov models, in a sequential data setting. Given a collapsed hidden Markov Model, we break its long Markov chain into a set of short subchains. We propose a novel sum-product algorithm to update the posteriors of the subchains, taking into account their boundary transitions due to the sequential dependencies. Our experiments on two discrete datasets show that our collapsed algorithm is scalable to very large datasets, memory efficient and significantly more accurate than the existing uncollapsed algorithm.