The range of interaction for a fitted point process model
of class "kppm"
may defined as the smallest number \(R\) such that
\(g(r)=1\) for all \(r\ge R\), where \(g\) is the pair
correlation function.
For many models the range is infinite, but one
may instead use a value where the pair correlation function is
sufficiently close to 1. The argument epsilon specifies the
tolerance; there is a sensible default.