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arXiv 1702.00308stat.MEstat.OT
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网络形成模型的近似变分估计

Approximate Variational Estimation for a Model of Network Formation

Angelo Mele, Lingjiong Zhu

摘要:

我们开发了指数随机图模型(ERGMs)的近似估计方法,其可能性与一个棘手的归一化常数成正比。通常的方法近似这个常数与蒙特卡罗模拟,但收敛可能是指数缓慢。我们提出了一种确定性的方法,基于ERGM的归一化常数的变分平均场近似。我们计算任何网络大小的近似误差的上下界,适应非线性大偏差的结果。这转化为真实似然和平均场似然之间距离的界限。蒙特卡罗模拟表明,在实践中,我们的确定性方法比我们的保守的理论近似界限暗示,为一大类模型。

英文摘要:

We develop approximate estimation methods for exponential random graph models (ERGMs), whose likelihood is proportional to an intractable normalizing constant. The usual approach approximates this constant with Monte Carlo simulations, however convergence may be exponentially slow. We propose a deterministic method, based on a variational mean-field approximation of the ERGM's normalizing constant. We compute lower and upper bounds for the approximation error for any network size, adapting nonlinear large deviations results. This translates into bounds on the distance between true likelihood and mean-field likelihood. Monte Carlo simulations suggest that in practice our deterministic method performs better than our conservative theoretical approximation bounds imply, for a large class of models.

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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