论文标题
Markov链蒙特卡洛模拟的几何适用于Langevin动力学
Geometrically adapted Langevin dynamics for Markov chain Monte Carlo simulations
论文作者
论文摘要
马尔可夫链蒙特卡洛(MCMC)是从给定概率分布中采样最强大的方法之一,其中大都市调整后的langevin算法(MALA)是一种变体,其中分布的梯度用于更快的收敛。但是,在欧几里得框架中设置,MALA在较高的维度问题中或涉及各向异性密度的人的表现可能会差,因为样本空间的几何形状的潜在非欧几里得方面仍然没有任何意义。我们利用从差异几何形状和riemannian歧管上的随机演算的概念,以几何形式适应具有非平凡漂移项的随机微分方程。这种适应也称为随机发展。我们将此方法专门应用于langevin扩散方程,并到达几何适用的langevin动力学。这种新方法远远超过了MALA,MALA的某些歧管变体以及其他方法,例如Hamiltonian Monte Carlo(HMC),其适应性变体在Stan中实现了No-U-Turn Sampler(Nuts),尤其是因为问题的尺寸通常会增加Gala实际上是唯一成功的方法。通过几个数值示例可以证明这一点,其中包括广泛的概率分布和逻辑回归问题的参数估计。
Markov Chain Monte Carlo (MCMC) is one of the most powerful methods to sample from a given probability distribution, of which the Metropolis Adjusted Langevin Algorithm (MALA) is a variant wherein the gradient of the distribution is used towards faster convergence. However, being set up in the Euclidean framework, MALA might perform poorly in higher dimensional problems or in those involving anisotropic densities as the underlying non-Euclidean aspects of the geometry of the sample space remain unaccounted for. We make use of concepts from differential geometry and stochastic calculus on Riemannian manifolds to geometrically adapt a stochastic differential equation with a non-trivial drift term. This adaptation is also referred to as a stochastic development. We apply this method specifically to the Langevin diffusion equation and arrive at a geometrically adapted Langevin dynamics. This new approach far outperforms MALA, certain manifold variants of MALA, and other approaches such as Hamiltonian Monte Carlo (HMC), its adaptive variant the no-U-turn sampler (NUTS) implemented in Stan, especially as the dimension of the problem increases where often GALA is actually the only successful method. This is evidenced through several numerical examples that include parameter estimation of a broad class of probability distributions and a logistic regression problem.