I made a diagram. The names follow the PyTorch docs, although I renamed num_layers to w. output comprises all the hidden states in the last layer (“last” depth-wise, not time-wise). (h_n, c_n) comprises the hidden states after the last timestep, t = n, so you could potentially feed them into another LSTM. The batch dimension … Read more
Sigmoid specifically, is used as the gating function for the three gates (in, out, and forget) in LSTM, since it outputs a value between 0 and 1, and it can either let no flow or complete flow of information throughout the gates. On the other hand, to overcome the vanishing gradient problem, we need a … Read more
So: One-to-one: you could use a Dense layer as you are not processing sequences: model.add(Dense(output_size, input_shape=input_shape)) One-to-many: this option is not supported well as chaining models is not very easy in Keras, so the following version is the easiest one: model.add(RepeatVector(number_of_times, input_shape=input_shape)) model.add(LSTM(output_size, return_sequences=True)) Many-to-one: actually, your code snippet is (almost) an example of this … Read more
I have stumbled upon this problem too and below is what I figured out. When training RNN (LSTM or GRU or vanilla-RNN), it is difficult to batch the variable length sequences. For example: if the length of sequences in a size 8 batch is [4,6,8,5,4,3,7,8], you will pad all the sequences and that will result … Read more