Hi,

I have implemented a hybdrid model with CNN & LSTM in both Keras and PyTorch, the network is composed by 4 layers of convolution with an output size of 64 and a kernel size of 5, followed by 2 LSTM layer with 128 hidden states, and then a Dense layer of 6 outputs for the classification.

In fact, i have juste implemented the DeepConvLSTM proposed here https://www.researchgate.net/publication/291172413_Deep_Convolutional_and_LSTM_Recurrent_Neural_Networks_for_Multimodal_Wearable_Activity_Recognition.

My problem is with PyTorch version, i’m getting around 18~19 % of accuracy, while Keras is giving 86~87%. I don’t understand why, i’m using the same parameters for both networks and the same optimizer RMSROP.

I also tried to use GRU instead of LSTM, but getting the same problem, seems like there is a probleme with the hybridation its selfs, but i can not figure it out.

here is my scripts

**Keras version :**

```
type or paste cdef ConvLSTM_Keras(input_shape):
from keras.models import Sequential
from keras.layers import Dense,Conv1D,LSTM
model = Sequential()
model.add(Conv1D(64, 5,
activation='relu',
input_shape=input_shape))
model.add(Conv1D(64, 5, activation='relu'))
model.add(Conv1D(64, 5, activation='relu'))
model.add(Conv1D(64, 5, activation='relu'))
model.add(LSTM(128,return_sequences=True))
model.add(LSTM(128,return_sequences=False))
model.add(Dense(6, activation='softmax'))
return model
model.compile(loss=keras.losses.categorical_crossentropy,
optimizer=keras.optimizers.rmsprop(
learning_rate=0.001
),
metrics=['accuracy'])
model.fit(x_train, y_train,
epochs=20,
batch_size=100,
verbose=1,
validation_data=(x_val, y_val))
```

**PyTorch Version**

```
def __init__(self):
super(SimpleCNN, self).__init__()
self.conv1 = torch.nn.Conv1d(in_channels=1, out_channels=64, kernel_size=5)
self.conv2 = torch.nn.Conv1d(in_channels=64,out_channels=64, kernel_size=5)
self.conv3 = torch.nn.Conv1d(in_channels=64, out_channels=64, kernel_size=5)
self.conv4 = torch.nn.Conv1d(in_channels=64, out_channels=64, kernel_size=5)
self.lstm1 = torch.nn.LSTM(
input_size= 545,
hidden_size=128,
num_layers=2,
)
self.fc2 = torch.nn.Linear(128, 6)
def forward(self, x):
x = F.relu(self.conv1(x))
x = F.relu(self.conv2(x))
x = F.relu(self.conv3(x))
x = F.relu(self.conv4(x))
x,_ = self.lstm1(x)
x = x[:, -1, :]
x = self.fc2(x)
return (x)
import torch.optim as optim
def createLossAndOptimizer(net, learning_rate=0.001):
# Loss function
loss = torch.nn.CrossEntropyLoss()
# Optimizer
optimizer = optim.rmsprop(net.parameters(), lr=learning_rate)
return (loss, optimizer)
```

Hope you can help me, thanks.

Nassim