Validation step: error when trying to return object

[mcomunita]

Hi,

As part of my validation_step in a AE I am trying to return an object containing input and reconstructed output.

validation_epoch_end does not get the accumulated outputs.

Here's the code:

def validation_step(self, batch, batch_idx):
        x, x_recon, _, _, _ = self.forward(batch)
        outputs = {
            'x': x,
            'x_recon': x_recon
        }
        return outputs

these are the shapes:
x.shape: torch.Size([2, 1, 257, 63])
x_recon.shape: torch.Size([2, 1, 257, 63])

and this is what validation_step_outputs looks like:
[{'x': tensor(0.0033, device='cuda:0'), 'x_recon': tensor(-0.0102, device='cuda:0')}]

Any idea why?

Thanks

[rohitgr7]

hey @mcomunita!

this shouldn't happen. Quick ques: are you using DP?

[mcomunita]

Hi @rohitgr7,

Yes, I am using DP. It took me a while to figure it out but I saw on the documentation that in such a case I need to also implement validation_step_end, which I am now using to accumulate the outputs from validation_step

You can consider this solved.

Thanks

[rohitgr7]

Also we recently patched this, so it won't reduce any other outputs except the loss. Will be available in the next release :)