The forecasting results of MAPE and RMSE by sequentially adding the grouped features of Table 4 into LSTM for the indicator of import of coal.

The grouped features with different correlation coefficients were added in descending order. The column of ‘Single feature’ denotes that only the targeted indicator (without features) was used to model for forecasting. The columns of ‘Grouped features with different correlation coefficient ranges’ denotes that the features with corresponding correlation coefficients were used to model for forecasting. For example, the column of ‘0.90–1.00’ denotes that the features with correlation coefficients of 0.90–1.00 were used to model.