论文标题
贝叶斯语境树:离散时间序列的建模和精确推断
Bayesian Context Trees: Modelling and exact inference for discrete time series
论文作者
论文摘要
我们为一类高阶,可变的记忆马尔可夫链开发了一个新的贝叶斯建模框架,并引入了相关的方法学工具集合,以通过离散时间序列进行精确推断。我们表明,上下文树加权算法的一个版本可以准确计算先前的预测可能性(在模型和参数上平均),并引入了两种相关的算法,这些算法最有可能识别posteriori模型并计算其精确的后验概率。所有三种算法都是确定性的,并且具有线性时间复杂性。还提供了一个可变维度马尔可夫链蒙特卡洛采样器的家族,从而进一步探索了后部。通过仿真实验和现实世界应用,通过金融,遗传学,神经科学和动物交流的数据来说明拟议方法在模型选择,马尔可夫顺序估计和预测中的性能。相关算法在R软件包BCT中实现。
We develop a new Bayesian modelling framework for the class of higher-order, variable-memory Markov chains, and introduce an associated collection of methodological tools for exact inference with discrete time series. We show that a version of the context tree weighting algorithm can compute the prior predictive likelihood exactly (averaged over both models and parameters), and two related algorithms are introduced, which identify the a posteriori most likely models and compute their exact posterior probabilities. All three algorithms are deterministic and have linear-time complexity. A family of variable-dimension Markov chain Monte Carlo samplers is also provided, facilitating further exploration of the posterior. The performance of the proposed methods in model selection, Markov order estimation and prediction is illustrated through simulation experiments and real-world applications with data from finance, genetics, neuroscience, and animal communication. The associated algorithms are implemented in the R package BCT.