R/var_types.R

In ezsummary: Generate Data Summary in a Tidy Format

#' Attach the variable type information with the dataset
#'
#' @description In order to analyze variables in the most appropriate way using
#' this \code{ezsummary} package, you'd better let the computer know what types
#' of data (quantitative or categorical) you are asking it to compute. This
#' function will attach a list of types you entered with the datasets so
#' functions down the stream line can read these information and analyze based
#' on that. The information is stored in the attributes of the dataset
#'
#' @param tbl A data.frame
#' @param types Character vector of length equal to the number of variables in
#' the dataset. Use "q" and "c" to denote quantitative and categorical variables.
#'
#' @export

var_types <- function(tbl, types) {
  if (!is.data.frame(tbl)) {
    stop("Please supply a data.frame/data.table as the value of tbl")
  }

  if (nchar(types) != length(attributes(tbl)$names)){
    stop("The length of the string you entered doesn't match the number',
         ' of variables")
  }

  if (grepl("[^cq]", types)){
    stop('Unrecognizable character(s) detected!! Please review your ',
         'input and use "q" and "c" to denote quantitative and ',
         'categorical variables')
  }

  attributes(tbl)$var_types <- unlist(strsplit(types, ""))

  return(tbl)
}

#' Automaticall assign var_types to the attributes
#'
#' @description If the user did not provide var_types, the function will
#' preassume every variables to be quantitative variables. If a variable's type
#' is character but either the user or the automatic step said it's a
#' quantitative variable, the var_types attribute for that variable will be
#' overwritten as categorical variable. At the same time, a warning message
#' will be printed on the screen.
#'
#' @param tbl The imported data.frame
#'
#' @export
auto_var_types <- function(tbl) {
  col_class <- sapply(tbl, class)
  if (is.null(attributes(tbl)$var_types)) {
    attributes(tbl)$var_types <- ifelse(col_class == "numeric", "q", "c")
  }
  if (length(attributes(tbl)$vars) != 0) {
    attributes(tbl)$var_types[names(tbl) %in% attributes(tbl)$vars] <- "g"
  }
  return(tbl)
}