Subsampling is an effective approach to alleviate the computational burden associated with large-scale datasets. Nevertheless, existing subsampling estimators incur a substantial loss in estimation efficiency compared to estimators based on the full dataset. Specifically, the convergence rate of existing subsampling estimators is typically $n^{-1/2}$ rather than $N^{-1/2}$, where $n$ and $N$ denote the subsample and full data sizes, respectively. This paper proposes a subsampled one-step (SOS) method to mitigate the estimation efficiency loss utilizing the asymptotic expansions of the subsampling and full-data estimators. The resulting SOS estimator is computationally efficient and achieves a fast convergence rate of $\max\{n^{-1}, N^{-1/2}\}$ rather than $n^{-1/2}$. We establish the asymptotic distribution of the SOS estimator, which can be non-normal in general, and construct confidence intervals on top of the asymptotic distribution. Furthermore, we prove that the SOS estimator is asymptotically normal and equivalent to the full data-based estimator when $n / \sqrt{N} \to \infty$.Simulation studies and real data analyses were conducted to demonstrate the finite sample performance of the SOS estimator. Numerical results suggest that the SOS estimator is almost as computationally efficient as the uniform subsampling estimator while achieving similar estimation efficiency to the full data-based estimator.
自助法是一种流行的和强大的方法,用于评估估计和推理方法的精度。然而,对于日益普遍的大规模数据集,引导变得过于昂贵的计算和其可行性是值得怀疑的,即使与现代并行计算平台。最近,Kleiner,Talwalkar,Sarkar和Jordan(2014)提出了一种称为BLB(Bag of Little Bootstrap)的方法,用于大规模数据,该方法在计算上更具可扩展性,并且很少牺牲统计准确性。基于BLB和快速双自举的思想,我们提出了一种新的重采样方法,即下采样双自举,它既适用于独立数据,也适用于时间序列数据。我们建立了独立和依赖的情况下,在温和的条件下的二次抽样双自助的一致性。在方法上,二次抽样双自举是优于BLB的运行时间,更多的样本覆盖率和自动实现较少的调整参数,为给定的时间预算。它的优点相对于BLB和自助也证明了在数值模拟和数据说明。
How Fast Do Signatures Learn? Statistical Theory and Applications for Path Regression
Mathematical Institute, University of Oxford(牛津大学数学研究所);Center for Data Science, Peking University(北京大学数据科学中心);School of Mathematical Sciences, Peking University(北京大学数学科学学院);Oxford Man Institute, University of Oxford(牛津大学牛津人学研究所);Center for Statistical Science, Peking University(北京大学统计科学中心)
SLOE: A Faster Method for Statistical Inference in High-Dimensional Logistic Regression
Google Research(谷歌研究院);Google Health(谷歌健康)
逻辑斯谛回归仍然是应用统计学、机器学习和数据科学中使用最广泛的工具之一。然而,在中等高维的问题,其中的功能$d$的数量是一个不可忽略的部分的样本大小$n$,逻辑斯谛回归最大似然估计(MLE),和统计程序的基础上,其分布的大样本近似,表现不佳。最近,Sur和Candès(2019)表明,这些问题可以通过在这个高维区域中应用MLE采样分布的新近似来纠正。不幸的是,这些校正在实践中难以实现,因为它们需要\emph{signal strength}的估计,\emph{signal strength}是逻辑斯谛回归的基础参数$β$的函数。为了解决这个问题,我们提出了SLOE,一个快速和直接的方法来估计信号强度的逻辑斯谛回归。SLOE的关键见解是,Sur和Candès(2019)校正可以根据\emph{corrupted signal strength}重新参数化,\emph{corrupted signal strength}仅是估计参数$\widehat β$的函数。我们提出了这个量的估计,证明它是一致的,在相关的高维制度,并表明使用SLOE的维数校正是准确的有限样本。与现有的ProbeFrontier启发式相比,SLOE在概念上更简单,速度更快,适合日常使用。我们证明了常规维度校正的重要性,在心脏病数据集从UCI存储库,和基因组学应用程序使用的数据从英国生物银行。我们为这种方法提供了一个…