For clarification:
I used DataLoader to bring the data in the shape I needed.
Before, I had 2 x 400 numpy array for input, and 3 x 400 for output. I have flattened those to tensors of size 800 and 1200 before transforming them to tensors of 750 x 800 and 750 x 1200, respectively.
The input to the training loop then is each row of size 800. Because I couldn’t get the dataloader to handle two rows for input and three rows for output at the same time, I did this little maneuver.
Edit:
Yes! Thank you, I had changed the training loop to the range of x, it worked when I changed it back to the tensor itself.