Recall that the symbols in the GHMM are represented by either a or a .
This method assumes the system is in steady state, and calculates the long term
time average (when ) of the values of the emitted symbols. In
other words, it calculates the expected symbol value that will be observed in
one symbol emission.
Usages: symb_tavg()
Output: Prints the symbol's average value emitted, over time, when .