mpezeshki
commented
9 years ago Hi, Let's say we have 3 classes (a, b, and c), batch-size of 1, and 2 time-steps. So the probabilities are:
time | a | b | c | blank |
-------------------------------------------
0 | 0.2 | 0.4 | 0.3 | 0.1 |
-------------------------------------------
1 | 0.35 | 0.15 | 0.2 | 0.3 |
-------------------------------------------Let's suppose the output sequence is b, a, a, b, c. (Actually blanks will be added too but at this point let's just ignore it.) Then the output must be:
time | b | a | a | b | c
----------------------------------------------
0 | 0.4 | 0.2 | 0.2 | 0.4 | 0.3
----------------------------------------------
1 | 0.15 | 0.35 | 0.35 | 0.15 | 0.2
----------------------------------------------So basically it replicates those probabilities to the length of the output sequence. About the mask, I don't remember why did I do this, but now Kyle has a new version of code which you may find useful: https://gist.github.com/kastnerkyle/ca851e39229551208c0d#file-minibatch_ocr-py-L175
Hello, I am doing some research on TIMIT and I have to use CTC in my model. I read ctc_cost.py but I can not understand the function: class_batch_to_labeling_batch(y, y_hat, y_hat_mask=None). In comments, y_hat is T x B x (C+1) matrix and y_hat_mask is T x B matrix. In line 65: y_hat = y_hat * y_hat_mask.dimshuffle(0, 'x', 1) I am puzzled because y_hat_mask.dimshuffle(0, 'x', 1) is T x 1 x B matrix and it can not multiply with y_hat which is T x B x (C+1) matrix. In addition, I tried to run this function in Ipython notebook and it reported an error. Could you please explain why it is y_hat = y_hat * y_hat_mask.dimshuffle(0, 'x', 1) and what is res in the function? Thanks.