The eval metric is always the same.
Ans I found the model never optimized.
I step with the input flow to the model, and I found all Variables have grad_fn.
Then I use backward function.
I try to have something with the grad by
[p.grad.mean() for p in params if p.grad is not None],
The shown data is really small, e-3~e-9.
So, maybe my model is wrong?
I check much times, and it seems no problem.
What can I do next?