shuffle the datasets first

[CorcovadoMing]

should shuffle the datasets first in order to get the correct validation result

[wepe]

CorcovadoMing, you are right. Many thanks!
And I think it is not necessary to shuffle the data each epoch, I will remove the same code following.

[CorcovadoMing]

It's hard to say whether shuffle in each epoch needed, but I think maybe it's a good idea to shuffle in each epochs to avoid a fixed training pattern

need more experiments to confirm which one is better :)