  The methods for studying the epoch of cosmic reionization vary from full
radiative transfer simulations to purely analytical models. While numerical
approaches are computationally expensive and are not suitable for generating
many mock catalogs, analytical methods are based on assumptions and
approximations. We explore the interconnection between both methods. First, we
ask how the analytical framework of excursion set formalism can be used for
statistical analysis of numerical simulations and visual representation of the
morphology of ionization fronts. Second, we explore the methods of training the
analytical model on a given numerical simulation. We present a new code which
emerged from this study. Its main application is to match the analytical model
with a numerical simulation. Then, it allows one to generate mock reionization
catalogs with volumes exceeding the original simulation quickly and
computationally inexpensively, meanwhile reproducing large scale statistical
properties. These mock catalogs are particularly useful for CMB polarization
and 21cm experiments, where large volumes are required to simulate the observed
signal.
