Internal function to estimate values of lambda needed for MCMC_simulation and prior probability of k clusters/anti-clusters for k=0,...,J
estimate_lambda(n.sim, J, prior.z, overlap, pi0)number of importance sampling iterations
maximum number of clusters/anti-clusters to consider
prior probability of each single zone
output of create_geo_objects: list with two elements: presence which lists for each area all the single zones it is present in and cluster_list for each single zone its component areas
prior probability of no clusters
estimates of lambda and prior.j
Wakefield J. and Kim A.Y. (2013) A Bayesian model for cluster detection. Biostatistics, 14, 752--765.