LGBM-CBFS: A Heuristic Feature Sampling Method Based on Tree Ensembles

Abstract

Gradient boosting decision tree (GBDT) is widely used because of its state-of-art performance in academia, industry, and data science competitions. The efficiency of the model is limited by the overwhelming training cost with the surge of data. A common solution is data reduction by sampling on training data. Current popular implementations of GBDT such as XGBoost and LightGBM both supports cut the search space by using only a random subset of features without any prior knowledge, which is ineffective and may lead the model fail to converge when sampling on a high-dimensional feature space with a small sampling rate assigned. To mitigate this problem, we proposed a heuristic sampling algorithm LGBM-CBFS, which samples features based on an available prior knowledge named "importance scores"to improve the performance and the effectiveness of GBDT. Experimental results indicate that LGBM-CBFS obtains a higher level of model accuracy than uniform sampling without introducing unacceptable time cost in the sparse high-dimensional scenarios.