Recurrent Neural Network
- Hard to train on long sequences
- Weights hold memory
- Implicit
- Lots to remember
## Text Analysis
- Train sequences of text character-by-character
- Maintains state vector representing data up to current token
- Combines state vector with next token to create new vector
- In theory, info from one token can propagate arbitrarily far down the sequence
- In practice suffers from vanishing gradient
- Can't extract precise information about previous tokens
![rnn-input](../../../img/rnn-input.png)
![rnn-recurrence](../../../img/rnn-recurrence.png)