Points of the marked Poisson process are generated in continuous time, using the following procedure:
First, a trajectory of the underlying Poisson process is generated. Then, the mark series is generated
using a d-state Markov chain. The mark series takes values in 1,2,...,d and determines in which of the d processes
the points occur.
The marginal processes defined by the marks are not Poisson unless the generated marks are
independent observations, see Isham (1980).
A transition matrix \(P = (p_{ij})\) with equal rows leads to \(d\) independent point processes, and the more
similar the rows of P, the less dependent the resulting processes. The spectral gap (SpecGap)
measures the dependence between the generated processes, see Abaurrea et al. (2014).
Tha marginal processes of the marked process can be optionally plotted using dplot=TRUE.