R/project_to.R

In grattan: Australian Tax Policy Analysis

#' Simple projections of the annual 2\% samples of Australian Taxation Office tax returns.
#' 
#' @param sample_file A \code{data.table} matching a 2\% sample file from the ATO.
#' See package \code{taxstats} for an example.
#' @param to_fy A string like "1066-67" representing the financial year for which forecasts of the sample file are desired. 
#' @param fy.year.of.sample.file The financial year of \code{sample_file}. See \code{\link{project}} for the default.
#' @param ... Other arguments passed to \code{\link{project}}.
#' @return A sample file with the same number of rows as \code{sample_file} but 
#' with inflated values as a forecast for the sample file in \code{to_fy}. 
#' If \code{WEIGHT} is not already a column of \code{sample_file}, it will be added and its sum
#' will be the predicted number of taxpayers in \code{to_fy}.
#' @export

project_to <- function(sample_file, to_fy, fy.year.of.sample.file = NULL, ...) {
  
  if (is.null(fy.year.of.sample.file)) {
    fy.year.of.sample.file <-
      match(nrow(sample_file), c(254318L, 258774L, 263339L, 269639L, 277202L))
    if (is.na(fy.year.of.sample.file)) {
      stop("`fy.year.of.sample.file` was not provided, yet its value could not be ",
           "inferred from nrow(sample_file) = ", nrow(sample_file), ". Either use ", 
           "a 2% sample file of the years 2012-13, 2013-14, 2014-15, 2015-16, 2016-17, or ", 
           "supply `fy.year.of.sample.file` manually.")
    }
    fy.year.of.sample.file <- 
      c("2012-13", "2013-14", "2014-15", "2015-16", "2016-17")[fy.year.of.sample.file]
  }
  
  h <- as.integer(fy2yr(to_fy) - fy2yr(fy.year.of.sample.file))
  project(sample_file = sample_file, h = h,
          fy.year.of.sample.file = fy.year.of.sample.file,
          ...)
}