arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2106.01682cs.LGstat.ML
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大规模概率回归的概率梯度提升机

Probabilistic Gradient Boosting Machines for Large-Scale Probabilistic Regression

University of Amsterdam(阿姆斯特丹大学)

Olivier Sprangers, Sebastian Schelter, Maarten de Rijke

摘要:

梯度提升机(GBM)在解决表格数据问题方面非常受欢迎。然而,从业者不仅对点预测感兴趣,而且对概率预测感兴趣,以便量化预测的不确定性。现有的基于GBM的解决方案很难创建这样的概率预测:它们要么需要训练多个模型,要么计算成本太高,无法用于大规模设置。我们提出了概率梯度提升机(PGBM),一种方法来创建概率预测与一个单一的合奏决策树在计算上有效的方式。PGBM将决策树中的叶子权重近似为随机变量,并通过随机树集成更新方程近似数据集中每个样本的均值和方差。这些学习的时刻允许我们在训练后从指定的分布中进行采样。我们通过经验证明了PGBM与现有最先进方法相比的优势:(i)PGBM在不损害单个模型中的点性能的情况下实现概率估计,(ii)PGBM仅通过单个模型学习概率估计(并且不需要多参数提升),从而在大型数据集上提供了比现有的最先进的方法高出几个数量级的加速,PGBM在具有复杂可微损失函数的任务中实现了准确的概率估计,例如分层时间序列问题,我们观察到点预测性能提高了10%,概率预测性能提高了300%。

英文摘要:

Gradient Boosting Machines (GBM) are hugely popular for solving tabular data problems. However, practitioners are not only interested in point predictions, but also in probabilistic predictions in order to quantify the uncertainty of the predictions. Creating such probabilistic predictions is difficult with existing GBM-based solutions: they either require training multiple models or they become too computationally expensive to be useful for large-scale settings. We propose Probabilistic Gradient Boosting Machines (PGBM), a method to create probabilistic predictions with a single ensemble of decision trees in a computationally efficient manner. PGBM approximates the leaf weights in a decision tree as a random variable, and approximates the mean and variance of each sample in a dataset via stochastic tree ensemble update equations. These learned moments allow us to subsequently sample from a specified distribution after training. We empirically demonstrate the advantages of PGBM compared to existing state-of-the-art methods: (i) PGBM enables probabilistic estimates without compromising on point performance in a single model, (ii) PGBM learns probabilistic estimates via a single model only (and without requiring multi-parameter boosting), and thereby offers a speedup of up to several orders of magnitude over existing state-of-the-art methods on large datasets, and (iii) PGBM achieves accurate probabilistic estimates in tasks with complex differentiable loss functions, such as hierarchical time series problems, where we observed up to 10% improvement in point forecasting performance and up to 300% improvement in probabilistic forecasting performance.

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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