Sorry, I should have explained more clearly.
I actually do not concatenate along dimension 0, I concatenate along dimension 2.
I actually perform:
torch.cat( [word_embeds[i,:,:].view(1, batch_size, -1), char_rep[i,:,:].view(1, batch_size, -1)], 2 )
because all concatenated Variables are actually 3-dimensional, and I want to concatenate along the features dimension (the other two are sequence_length and batch_size).