Hi,
The Baum-Welch algorithm is designed to estimate both the transition and emission probabilities based on the observed sequence. It iteratively updates both sets of probabilities to maximize the likelihood of the observed data.
The MATLAB function hmmtrain can be trained either using the original Baum-Welch Algorithm or the original Viterbi Algorithm. It cannot be customized to keep the emission probabilities constant as that would require a change in the algorithm itself.
If you specifically want to keep the emission probabilities constant and update only the transition probabilities, you will need to implement your own version of the Baum-Welch algorithm.
Hope this helps.
