Data-Driven Fault Diagnosis for Rolling Bearing Based on DIT-FFT and XGBoost

Table 3

Main parameters information of XGBoost

Number	Parameter	Implication	Default value
1	max_depth	Maximum depth of a tree	6
2	gamma	Minimum loss function decline value	0
3	max_delta_step	Maximum delta step we allow each leaf output to be	0
4	lambda	L2 regularization term on weights	1
5	alpha	L1 regularization term on weights	0
6	min_child_weight	Minimum sum of instance weight needed in a child	1
7	Eta	Step size shrinkage used in update to prevent overfitting	0.3
8	Subsample	Subsample ratio of the training instances	1