Extract discrete samples from a skeleton
DiscreteSamples(skeletonList, n_samples, coordinate = -1L)a piecewise deterministic skeleton (consisting of Times, Points and Velocities) returned by a sampler
number of samples to obtain
if specified, only obtain samples of the specified coordinate, otherwise obtain samples of all coordinates
Returns a list containing the extracted samples and the times (on the continuous time scale) at which the samples are extracted