arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1509.02451math.STstat.TH
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奇异多元正态模型中改进的二阶估计

Improved Second Order Estimation in the Singular Multivariate Normal Model

Didier Chételat, Martin T. Wells

摘要:

我们考虑的问题,估计协方差和精度矩阵,以及相关的判别系数,从正常的数据时,协方差阵的秩是严格小于其维数和可用的样本量。使用无偏风险估计,我们构造新的估计,通过最小化上界的差异,在几个类的风险。经验证明,我们的建议估计提供了实质性的改进,经典的方法。

英文摘要:

We consider the problem of estimating covariance and precision matrices, and their associated discriminant coefficients, from normal data when the rank of the covariance matrix is strictly smaller than its dimension and the available sample size. Using unbiased risk estimation, we construct novel estimators by minimizing upper bounds on the difference in risk over several classes. Our proposal estimates are empirically demonstrated to offer substantial improvement over classical approaches.

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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