Performs the drifting Markov models (DMM) which are
non-homogeneous Markov models designed for modeling the heterogeneities of
sequences in a more flexible way than homogeneous Markov chains or even
hidden Markov models. In this context, we developed an R package dedicated to
the estimation, simulation and the exact computation of associated reliability
of drifting Markov models. The implemented methods are described in
Vergne, N. (2008),