Functions for determining and evaluating high-risk zones and
simulating and thinning point process data, as described in 'Determining
high risk zones using point process methodology - Realization by building
an R package' Seibold (2012) < http://highriskzone.r-forge.r-project.org/Bachelorarbeit.pdf>
and 'Determining high-risk zones for unexploded World War II bombs by using point
process methodology', Mahling et al. (2013)