R/data-cars93.R

In OpenIntroStat/openintro: Datasets and Supplemental Functions from 'OpenIntro' Textbooks and Labs

#' cars93
#'
#' A data frame with 54 rows and 6 columns. This data is a subset of the
#' \code{Cars93} dataset from the \code{MASS} package.
#'
#' These cars represent a random sample for 1993 models that were in both
#' \emph{Consumer Reports} and \emph{PACE Buying Guide}. Only vehicles of type
#' \code{small}, \code{midsize}, and \code{large} were include.
#'
#' Further description can be found in Lock (1993). Use the URL
#' \url{http://jse.amstat.org/v1n1/datasets.lock.html}.
#'
#' @name cars93
#' @docType data
#' @format A data frame with 54 observations on the following 6 variables.
#' \describe{
#'   \item{type}{The vehicle type with levels \code{large}, \code{midsize},
#'   and \code{small}.}
#'   \item{price}{Vehicle price (USD).}
#'   \item{mpg_city}{Vehicle mileage in city (miles per gallon).}
#'   \item{drive_train}{Vehicle drive train with levels \code{4WD}, \code{front},
#'   and \code{rear}.}
#'   \item{passengers}{The vehicle passenger capacity.}
#'   \item{weight}{Vehicle weight (lbs).}
#' }
#' @source Lock, R. H. (1993) 1993 New Car Data. \emph{Journal of Statistics
#' Education} 1(1).
#' @keywords datasets
#' @examples
#'
#' library(ggplot2)
#'
#' # Vehicle price by type
#' ggplot(cars93, aes(x = price)) +
#'   geom_histogram(binwidth = 5) +
#'   facet_wrap(~type)
#'
#' # Vehicle price vs. weight
#' ggplot(cars93, aes(x = weight, y = price)) +
#'   geom_point()
#'
#' # Milleage vs. weight
#' ggplot(cars93, aes(x = weight, y = mpg_city)) +
#'   geom_point() +
#'   geom_smooth()
"cars93"