训练得到的loss是负值？

[chenqq1]

Training epoch: 0 loss: 1.3787947255539994
Training epoch: 1 loss: -0.11686869635937157
Validation dataset epoch: 1 loss: 4.276391523665396 mean_err: tensor(1.0776)final_err: tensor(2.1968)
Training epoch: 2 loss: -0.44195691734777687
Validation dataset epoch: 2 loss: 2.9025856962555965 mean_err: tensor(1.0149)final_err: tensor(2.0672)
Training epoch: 3 loss: -0.6255790152767639
Validation dataset epoch: 3 loss: 2.818588351265624 mean_err: tensor(1.0031)final_err: tensor(2.0612)
Training epoch: 4 loss: -0.7745512770007141
Validation dataset epoch: 4 loss: 2.661308268945793 mean_err: tensor(1.0141)final_err: tensor(2.0460)
Training epoch: 5 loss: -0.8871525505268626
Validation dataset epoch: 5 loss: 1.9109164989585503 mean_err: tensor(0.9268)final_err: tensor(1.8676)
Training epoch: 6 loss: -0.9383222575299442
Validation dataset epoch: 6 loss: 1.9576881097950816 mean_err: tensor(0.9330)final_err: tensor(1.8477)
Training epoch: 7 loss: -1.0259218493572857
Validation dataset epoch: 7 loss: 1.6354501941723045 mean_err: tensor(0.9228)final_err: tensor(1.8636)