Prerequisites & Notation

This chapter requires nn.Module and training loop (Chapter 26). Familiarity with time-series data and basic sequence processing is helpful.

nn.Module and training loops (Chapter 26)(Review ch26)
Self-check: Can you train a PyTorch model on batched data?
Backpropagation and gradient flow (Chapter 26)(Review ch26)
Self-check: Do you understand vanishing gradients in deep networks?

Symbol	Meaning	Introduced
$\\mathbf{h}_t$	Hidden state at time step $t$	s01
$\\mathbf{x}_t$	Input at time step $t$	s01
$T$	Sequence length	s01
$\\mathbf{f}_t, \\mathbf{i}_t, \\mathbf{o}_t$	LSTM forget, input, output gates	s01
$\\mathbf{c}_t$	LSTM cell state	s01