df: DataFrame with "state" (integer, 1 and 2 clear state, 3 - mixed state), "duration" (double), "irandom" (integer, 1-based index of a random cluster), "run_start" (integer, 1 for the first entry of the run, 0 otherwise), "session_tmean" (double)
normalized_tau: DoubleVector A normalized tau value for each random cluster / individual. Thus, its length must be equal to the number of unique indexes in df["irandom"].
mixed_state: DoubleVector A values used for the mixed state for each random cluster / individual. Thus, its length must be equal to the number of unique indexes in df["irandom"].
history_init: DoubleVector, size 2. Initial values of history for a run.
Returns
NumericMatrix, size df.nrows() × 2. Computed history values for each state.