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arXiv 1603.03028stat.ME
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条件Copula的高斯过程单指标模型

Gaussian Process Single Index Models for Conditional Copulas

Evgeny Levi, Radu V. Craiu

摘要:

参数条件Copula模型允许Copula参数根据未知的校准函数随一组协变量而变化。基于单指数模型(SIM)的光滑校准函数集,通过稀疏高斯过程(GP)先验分布,提出了二元条件Copula校准函数的灵活贝叶斯推断.通过从全后验分布进行马尔可夫链蒙特卡罗采样,联合完成来自边缘分布和校准函数的参数估计。一个新的条件交叉验证伪边际(CCVML)标准,以执行copula选择,并修改使用基于置换的程序来评估数据支持的简化假设。估计方法和模型选择标准的性能进行了研究,通过一系列的模拟使用正确的和错误指定的模型与克莱顿,弗兰克和高斯copula和涉及红葡萄酒的功能的数值应用。

英文摘要:

Parametric conditional copula models allow the copula parameters to vary with a set of covariates according to an unknown calibration function. Flexible Bayesian inference for the calibration function of a bivariate conditional copula is proposed via a sparse Gaussian process (GP) prior distribution over the set of smooth calibration functions for the single index model (SIM). The estimation of parameters from the marginal distributions and the calibration function is done jointly via Markov Chain Monte Carlo sampling from the full posterior distribution. A new Conditional Cross Validated Pseudo-Marginal (CCVML) criterion is introduced in order to perform copula selection and is modified using a permutation-based procedure to assess data support for the simplifying assumption. The performance of the estimation method and model selection criteria is studied via a series of simulations using correct and misspecified models with Clayton, Frank and Gaussian copulas and a numerical application involving red wine features.

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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