Data loader is changing label shapes in GRU

jagoul: <p>I am training a GRU/LSTM  for time-series prediction, I already tested the model in a classic way  by splitting the data between sequence and labels and everything is working fine and the shapes looks like the following inside the forward pass and the main training :</p>
<pre><code class="lang-auto">x in forward torch.Size([32, 90, 7])
h in forward torch.Size([2, 32, 128])
x in train torch.Size([32, 90, 7])
label in train torch.Size([32, 90, 7])
</code></pre>
<p>When I tried to to distribute the training set on diffirent clients/gatweways to train the model in a federated way like this :</p>
<pre><code class="lang-auto">federated_train_loader = sy.FederatedDataLoader(federated_train_dataset, shuffle=True, batch_size=batch_size, drop_last=True)
federated_test_loader = sy.FederatedDataLoader(federated_test_dataset, shuffle=False, batch_size=batch_size, drop_last=True)
</code></pre>
<p>I checked the federated data loader using pysft and has the same inputs and labels shapes as the previous experiments. but when I try to train and print out the tensors I got the following shapes :</p>
<pre><code class="lang-auto">x :torch.Size([32, 90, 7])
labels :torch.Size([32, 1])
</code></pre>
<p>Obviously my label shape is not in th correct size anymore but I don’t know where the changes happened , I am providing the training function for more information:</p>
<pre><code class="lang-auto">def train(federated_train_loader, learn_rate, hidden_dim=256, EPOCHS=1, model_type="GRU"):
    
    # Setting common hyperparameters
    input_dim = next(iter(federated_train_loader))[0].shape[2]
    print('input dim {}'.format(input_dim))
    output_dim = 1
    n_layers = 2
    # Instantiating the models
    if model_type == "GRU":
        model = GRUNet(input_dim, hidden_dim, output_dim, n_layers)
    else:
        model = LSTMNet(input_dim, hidden_dim, output_dim, n_layers)
    #model.to(device)
    
    # Defining loss function and optimizer
    criterion = nn.MSELoss()
    optimizer = torch.optim.SGD(model.parameters(), lr=learn_rate)
    
    model.train()
    print("Starting Training of {} model".format(model_type))
    epoch_times = []
    # Start training loop
    for epoch in range(1,EPOCHS+1):
        start_time = time.perf_counter()
        avg_loss = 0.
        counter = 0
        for inputs, labels in federated_train_loader:
            print('inputs :{}'.format(inputs.shape))
            print('labels :{}'.format(labels.shape))
            labels.view(-1, 2)
            print('labels :{}'.format(labels.shape))
            counter += 1
            worker = inputs.location
            h = model.init_hidden(batch_size).send(worker)
            if model_type == "GRU":
                h = h.data
            else:
                h = tuple([e.data for e in h])
            model.send(worker)
            model.zero_grad()
            out, h = model(inputs.to(device).float(), h)
            loss = criterion(out, label.to(device).float())
            loss.backward()
            optimizer.step()
            avg_loss += loss.item()
            if counter%200 == 0:
                print("Epoch {}......Step: {}/{}....... Average Loss for Epoch: {}".format(epoch, counter, len(federated_train_loader), avg_loss/counter))
        current_time = time.clock()
        print("Epoch {}/{} Done, Total Loss: {}".format(epoch, EPOCHS, avg_loss/len(federated_train_loader)))
        print("Time Elapsed for Epoch: {} seconds".format(str(current_time-start_time)))
        epoch_times.append(current_time-start_time)
    print("Total Training Time: {} seconds".format(str(sum(epoch_times))))
    return model
</code></pre>
<p>It is been while I am trying to solve it and I appreciate if anyone has a clue ?</p>