I would recommend taking a look at Bilingual Evaluation Understudy(BELU) score which is commonly used in evaluating machine translation results by sequence to sequence model. Here is the reference https://en.wikipedia.org/wiki/BLEU
are the LSTM cells on a given row all the same cell, with time flowing forward from left to right?
Yes this is correct
The x-axis on this figure is basically the time axis. Essentially all pink boxes in the same row are the same LSTM cell, with different inputs from the same sequence. At each timestep, the cell takes an input and produces an output which is ...