arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.13953math.STstat.TH
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高维随机森林的渐近性质

Asymptotic Properties of High-Dimensional Random Forests

Chien-Ming Chi, Patrick Vossler, Yingying Fan, Jinchi Lv

摘要:

随机森林算法作为一种灵活的非参数学习工具,即使在高维特征空间中也具有良好的经验性能,被广泛应用于各种实际应用中。揭示了潜在的机制,导致了一些重要的最近的理论结果的一致性的随机森林算法及其变种。然而,据我们所知,几乎所有现有的作品随机森林一致性在高维设置建立了各种修改的随机森林模型的分裂规则是独立的响应,少数例外假设简单的数据生成模型与二进制功能。鉴于此,在本文中,我们推导出的一致性率的随机森林算法与样本CART分裂标准,这是在该算法的原始版本中使用的,在一般的高维非参数回归设置通过偏差方差分解分析。我们的新理论结果表明,随机森林确实可以适应高维,并允许不连续的回归函数。我们的偏差分析明确地描述了随机森林偏差如何依赖于样本量、树高和列子采样参数。我们目前的结果的一些局限性进行了讨论。

英文摘要:

As a flexible nonparametric learning tool, the random forests algorithm has been widely applied to various real applications with appealing empirical performance, even in the presence of high-dimensional feature space. Unveiling the underlying mechanisms has led to some important recent theoretical results on the consistency of the random forests algorithm and its variants. However, to our knowledge, almost all existing works concerning random forests consistency in high dimensional setting were established for various modified random forests models where the splitting rules are independent of the response; a few exceptions assume simple data generating models with binary features. In light of this, in this paper we derive the consistency rates for the random forests algorithm associated with the sample CART splitting criterion, which is the one used in the original version of the algorithm, in a general high-dimensional nonparametric regression setting through a bias-variance decomposition analysis. Our new theoretical results show that random forests can indeed adapt to high dimensionality and allow for discontinuous regression function. Our bias analysis characterizes explicitly how the random forests bias depends on the sample size, tree height, and column subsampling parameter. Some limitations on our current results are also discussed.

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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