R/tidy_indice.R

In Ebedthan/tidygapminder: Easily Tidy Gapminder Datasets

#' Tidy Gapminder indicator single data sheet.
#'
#' @param filepath Path to indice data sheet.
#'
#' @return The indicator data sheet as a tidy data frame.
#'
#' @examples
#'
#' csv_filepath <- system.file("extdata/life_expectancy_years.csv",
#'                              package = "tidygapminder")
#' xlsx_filepath <- system.file(
#'                  "extdata/agriculture_land.xlsx",
#'                  package = "tidygapminder")
#'
#' tidy_indice(csv_filepath)
#' tidy_indice(xlsx_filepath)
#'
#' @export
tidy_indice <- function(filepath) {

  # Read data ---------------------------------
  if(!file.exists(filepath)) {
    stop("Input file not found: ", filepath)
  }
  ext <- tolower(tools::file_ext(filepath))
  df <- switch(
    ext,
    csv = readr::read_csv(filepath, col_types = readr::cols()),
    xlsx = readxl::read_xlsx(filepath),
    xls = readxl::read_xls(filepath),
    stop("Unknown extension: ", ext)
  )

  # To store indice name and description that is in first
  # cell of gapminder sheet.
  if (colnames(df)[1] == "country") {
    file_desc <- basename(tools::file_path_sans_ext(filepath))
  } else {
    file_desc <- colnames(df)[1]
  }

  # Tidy data ---------------------------------
  names(df)[1] <- "country"
  df <- tidyr::pivot_longer(data = df,
                            cols = -"country",
                            names_to = "year",
                            values_to = "indice"
                            )
  df$year <- as.numeric(df$year)
  names(df)[3] <- file_desc

  # Return data -------------------------------
  df
}