Issue about metrics

[night3759]

Thank you for your job! I got a question when I was reading the code, I found there is a mask operation during calculating the MAE and the MAPE. I don't know why there is a mask, and why the mask value is 5. I am looking forwark to your reply. Thank you.

[Echo-Ji]

Thanks for your comments.

• Why add a mask to MAE?
  The goal is to filter samples with small values that may be caused by noise or error (such as a loop sensor).

• Why add a mask to MAPE?
  The goal is to ignore very small values (e.g., 0.5/0.5=100%).

The mask operation is borrowed from AGCRN [1], and 5 is a common practice used in industry and academia.

[1] Bai, L.; Yao, L.; Li, C.; Wang, X.; and Wang, C. 2020. Adaptive graph convolutional recurrent network for traffic forecasting. NeurIPS, 33: 17804–17815.

[liuyixun]

如果这么做的话，mask_value以下的值就预测不到了，相当于完全放弃了mask_value以下的值了？