arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1907.03025math.STstat.MEstat.TH
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改进Lasso用于模型选择和预测

Improving Lasso for model selection and prediction

Piotr Pokarowski, Wojciech Rejchel, Agnieszka Soltys, Michal Frej, Jan Mielniczuk

摘要:

已知的是,双保持Lasso(TL)、SCAD或MCP校正Lasso的固有估计偏差。在本文中,我们提出了一种替代的方法来改善Lasso的预测模型与一般的凸损失函数,其中包括正常的线性模型,逻辑斯谛回归,分位数回归或支持向量机。对于给定的惩罚,我们对Lasso非零系数的绝对值进行排序,然后通过广义信息准则从一个小的嵌套族中选择最终模型。我们推导出该方法的选择误差的指数上界。这些结果证实,至少对于正常的线性模型,我们的算法似乎是模型选择理论的基准,因为它是建设性的,计算效率高,并导致一致的模型选择弱假设。该算法的构造性意味着,与TL、SCAD或MCP相比,一致性选择不依赖于未知参数作为锥可逆因子。相反,我们的算法只需要样本量,预测的数量和噪声参数的上界。我们在合成和真实世界的数据集上的数值实验表明,我们的算法的实现比研究凹正则化的实现更准确。我们的过程包含在R包“DMRnet”中,可在CRAN库中找到。

英文摘要:

It is known that the Thresholded Lasso (TL), SCAD or MCP correct intrinsic estimation bias of the Lasso. In this paper we propose an alternative method of improving the Lasso for predictive models with general convex loss functions which encompass normal linear models, logistic regression, quantile regression or support vector machines. For a given penalty we order the absolute values of the Lasso non-zero coefficients and then select the final model from a small nested family by the Generalized Information Criterion. We derive exponential upper bounds on the selection error of the method. These results confirm that, at least for normal linear models, our algorithm seems to be the benchmark for the theory of model selection as it is constructive, computationally efficient and leads to consistent model selection under weak assumptions. Constructivity of the algorithm means that, in contrast to the TL, SCAD or MCP, consistent selection does not rely on the unknown parameters as the cone invertibility factor. Instead, our algorithm only needs the sample size, the number of predictors and an upper bound on the noise parameter. We show in numerical experiments on synthetic and real-world data sets that an implementation of our algorithm is more accurate than implementations of studied concave regularizations. Our procedure is contained in the R package "DMRnet" and available on the CRAN repository.

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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