Create a suitable initial condition function from a set of restart
state. This takes care of a few bookkeping and serialisation
details and returns a function appropriate to pass to
particle_filter as initial.
particle_filter_initial(state)A matrix of state (rows are different states, columns are different realisations). This is the form of a slice pulled from a restart.
A function with arguments info, n_particles and pars
that will sample, with replacement, a matrix of state suitable
as a starting point for a particle filter. The info and
pars arguments are ignored.