#' @title popEpi: Functions for large-scale epidemiological analysis
#' @description
#' \pkg{popEpi} is built for the needs of registry-based (large-scale)
#' epidemiological analysis. This is in most part enabled by the
#' efficient \pkg{data.table} package for handling and aggregating large data sets.
#'
#' \pkg{popEpi} currently supplies some utility functions such as \code{\link{splitMulti}}
#' and \code{\link{get.yrs}} for preparing large data sets for epidemiological analysis.
#' Included are also a a few functions that can be used in
#' epidemiological analysis such as \code{\link{sir}} for estimating
#' standardized incidence/mortality ratios (SIRs/SMRs) and \code{\link{survtab}} for
#' estimating observed and relative/net survival as well as cumulative incidence
#' functions (CIFs). In particular, \code{survtab} implements the Ederer II
#' (Ederer and Heise (1959)) and
#' Pohar Perme estimators (Pohar Perme, Stare, and Esteve (2012)
#' \doi{10.1111/j.1541-0420.2011.01640.x}) and allows for easy
#' age-standardisation.
#'
#' Since there are many benefits to using \code{data.tables}, \pkg{popEpi} returns
#' outputs by default in the \code{data.table} format where appropriate.
#' Since \code{data.table}
#' objects are usually modified by reference, this may have surprising side
#' effects for users uninitiated in using \code{data.table}. To ensure
#' that appropriate outputs are in the \code{data.frame} format, set
#' \code{options("popEpi.datatable" = FALSE)}. However, \code{data.table}
#' usage is recommended due to better performance and testing coverage.
#' \code{data.table} is used
#' by most functions internally in both cases.
#'
#' @keywords internal
"_PACKAGE"
