Perl Exercises

1. In /home/bios546 is the file hmm_data.txt. It contains data pertaining to the rain-or-sun, walk-clean-shop hidden Markov model we discussed in class. The file has 2 line: the first line is the weather on each day (R or S), and the second line is the activity (W, C, or S). Input this data, then split it so that each character goes into a separate array element. There should thus be two arrays, one for weather and the other for activity, and the array elements should correspond so the same array index will give the weather and activity for the same day. Then, determine the emission probabilities for all 3 activities in each type of weather, and also the transition probabilities (R -> R, R -> S, S -> R, and S -> S).

2. Take what you wrote in #1 above and put the code that counts the transitions into a separate function that is called for each individual transition. Do the same for emissions: put the function that determines the type of emission and weather into a function that is called once for each day. Be sure to pass all variables in through the @_ array, and return all results with a return statement.