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arXiv 1709.04495stat.MLphysics.data-an
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连续时间Ising反问题:隐变量方法

Inverse Ising problem in continuous time: A latent variable approach

Christian Donner, Manfred Opper

摘要:

我们考虑逆伊辛问题,即从观测到的自旋轨迹的连续时间Glauber动力学模型的网络耦合的推断。通过引入两组辅助潜在随机变量,我们呈现的可能性到一个形式,它允许简单的迭代推理算法与分析更新。变量为:(1)Poisson变量,用于线性化指数项,这对于点过程似然是典型的;(2)Pólya-Gamma变量,其使得耦合参数中的似然是二次的。利用增广的似然估计,我们推导出一个期望最大化(EM)算法来获得网络参数的最大似然估计。使用第三组潜变量,我们通过L1正则化将期望最大化算法扩展到稀疏耦合。最后,我们开发了一个有效的近似贝叶斯推断算法,使用变分方法。我们证明了我们的算法的性能从伊辛模型模拟的数据。对于从一个更具生物学合理性的网络与尖峰神经元模拟的数据,我们表明,伊辛模型捕捉以及低顺序统计量的数据和伊辛耦合是如何相关的模拟网络的基础突触结构。

英文摘要:

We consider the inverse Ising problem, i.e. the inference of network couplings from observed spin trajectories for a model with continuous time Glauber dynamics. By introducing two sets of auxiliary latent random variables we render the likelihood into a form, which allows for simple iterative inference algorithms with analytical updates. The variables are: (1) Poisson variables to linearise an exponential term which is typical for point process likelihoods and (2) Pólya-Gamma variables, which make the likelihood quadratic in the coupling parameters. Using the augmented likelihood, we derive an expectation-maximization (EM) algorithm to obtain the maximum likelihood estimate of network parameters. Using a third set of latent variables we extend the EM algorithm to sparse couplings via L1 regularization. Finally, we develop an efficient approximate Bayesian inference algorithm using a variational approach. We demonstrate the performance of our algorithms on data simulated from an Ising model. For data which are simulated from a more biologically plausible network with spiking neurons, we show that the Ising model captures well the low order statistics of the data and how the Ising couplings are related to the underlying synaptic structure of the simulated network.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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