C2W2 viterbi backward & forward last columns in best_probs all = 0

For viterbi backwards I kept getting the wrong pred output for the last 6 values (all of them were #).


At first I was confused as to why this was happening. Then I found that several of the last columns in the best_probs matrix were all zeros, even though the matrix passed the viterbi_forward unit test. Because all of these columns were zero, the “highest probability” POS tag was chosen as the 0th index, which correlated with “#”.
Anyways, this is more of a question as to what went wrong with the best_probs matrix. I’m confused as to why several of the last columns are filled with zeros even though the unit test was passed.

Just figured out the problem. When making best_probs, I had the number of columns set to the entire vocab instead of just the test corpus.