Why .eval() is missing from this official Pytorch tutorial?

Here’s a DCGAN tutotial

When evaluating the performance, .eval() and .train() is completely ignored, no mention of them in the entire code. Why is that? Thanks.

EDIT: here, I can point to the exact line where I think this is missing

I have also noticed this. Even while I code, even if I miss eval and train. It didn’t have any effect on the result.

But the thing is how we are going about it does matter. We use eval because we won’t be interested in updating the weight of the network. While train weight updation happens. If we can turn off the gradients using torch no grad like your example, be it. It’s another way of approaching I think.

My understanding is that .eval() is to tell the network to disable dropout and batchnorm layers, where as the torch.no_grad() context is to disable gradient calculations. They are different concepts which happen to be used together during inference.

One possibility why .eval() is missing is because there are no dropout or batchnorm layers?

Dropout, batchnorm also seems like a proper answer. Can you let us know about that ?

There are. In both generator and discriminator.

It does have an effect. If I take 1000 examples from the generator, the images get whiter and whiter. To fix the performance I go to eval() mode.