# Result estimators

The Monte Carlo transport simulation is run to obtain statistical estimates
for integrals of the form:
**Failed to parse (unknown function "\dirvec"): **

where $f$ is a response function that can be evaluated at an arbitrary position
of the phase space, most typically a reaction cross section. These estimates
are based on the collection of simulated events (collisions, track-lengths,
surface crossings, etc.) that occur during the course of the simulated
random walk.

The estimates can be divided into: \begin{itemize} \item Analog estimates, based on recorded simulated physical events \item Implicit estimators, based the expected frequency of events \end{itemize} Implicit estimators are derived from analog estimators, with the purpose of obtaining better statistics. Even though the estimators introduced in the following can be used for calculating flux integrals, it should be noted that flux itself plays no role in Monte Carlo transport simulation.