R/calculate-rounding-digits.R

In Melinae/TabularManifest: Tabular Manifest

#' @name calculate_rounding_digits
#'
#' @title Internal function for calculating rounding digits for dataset variables
#'
#' @description An internal function (ie, that's not currently exposed/exported outside the package) for creating default bins for dataset variables.
#'
#' @param d_observed The \code{data.frame} with columns to calculate bins.

#' @return Returns a \code{numeric} vector, indicating how many rounding digits *might* be appropriate.
#'   Each element is an array with as many values as columns in \code{d_observed}.
#' @examples
#' calculate_rounding_digits(d_observed=freeny)
#' calculate_rounding_digits(d_observed=InsectSprays)
#' calculate_rounding_digits(d_observed=beaver1)

#' @export

calculate_rounding_digits <- function( d_observed ) {
  column_class <- base::vapply(X=d_observed, FUN=base::class, character(1))
  is_continuous <- (column_class  %in% c("numeric", "integer"))

  #TODO: mapply might be more memory efficient.  An entire data.frame is recreated (minus the non-contintuous variables).
  digits <- base::vapply(d_observed[,is_continuous, drop=FALSE], FUN=function( x ){1 - log10(scales:::precision(x))}, numeric(1))

  digits_all <- rep(x=1L, times=ncol(d_observed))
  digits_all[is_continuous] <- max(0L, digits)

  return( digits_all )
}

# calculate_rounding_digits(d_observed=freeny)
# calculate_rounding_digits(d_observed=InsectSprays)
# calculate_rounding_digits(d_observed=beaver1)