Vrettas Michail D, Opper Manfred, Cornford Dan
University of California, Berkeley, Berkeley, California 94720, USA.
Technical University Berlin, Berlin, D-10587, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Jan;91(1):012148. doi: 10.1103/PhysRevE.91.012148. Epub 2015 Jan 30.
This work introduces a Gaussian variational mean-field approximation for inference in dynamical systems which can be modeled by ordinary stochastic differential equations. This new approach allows one to express the variational free energy as a functional of the marginal moments of the approximating Gaussian process. A restriction of the moment equations to piecewise polynomial functions, over time, dramatically reduces the complexity of approximate inference for stochastic differential equation models and makes it comparable to that of discrete time hidden Markov models. The algorithm is demonstrated on state and parameter estimation for nonlinear problems with up to 1000 dimensional state vectors and compares the results empirically with various well-known inference methodologies.
这项工作引入了一种高斯变分平均场近似方法,用于可由普通随机微分方程建模的动力系统中的推理。这种新方法允许将变分自由能表示为近似高斯过程的边际矩的泛函。随着时间的推移,将矩方程限制为分段多项式函数,极大地降低了随机微分方程模型近似推理的复杂性,并使其与离散时间隐马尔可夫模型的复杂性相当。该算法在具有高达1000维状态向量的非线性问题的状态和参数估计中得到了验证,并通过实证将结果与各种著名的推理方法进行了比较。