R/getmm.R

In jjchern/ec300: R Functions for Econ 300

#' Get datasets from Mastering 'Metrics
#'
#' @param data A string specifying the name of a Mastering 'Metrics dataset. Datasets include "mlda", "banks"，and "deaths".
#' @param envir An environment in which to store the object. Default is the parent environment.
#' @return A dataframe.
#' @examples
#' getmm("mlda")
#' @import rio dplyr
#' @export
getmm = function(data, envir = parent.frame()) {
  if(data == "mlda"){
    dat = rio::import("http://masteringmetrics.com/wp-content/uploads/2015/01/AEJfigs.dta") %>%
      dplyr::tbl_df()
    assign(data, dat, envir = envir)
    invisible(dat)
  }

  if(data == "banks"){
    dat = rio::import("http://masteringmetrics.com/wp-content/uploads/2015/02/banks.csv") %>%
      dplyr::tbl_df()
    assign(data, dat, envir = envir)
    invisible(dat)
  }

  if(data == "deaths"){
    dat = rio::import("http://masteringmetrics.com/wp-content/uploads/2015/01/deaths.dta") %>%
      dplyr::tbl_df()
    assign(data, dat, envir = envir)
    invisible(dat)
  }

  info = paste0("All done. Try: View(", data, ").")
  message(info)
}