R/data-present.R

In openintro: Data Sets and Supplemental Functions from 'OpenIntro' Textbooks and Labs

#' Birth counts
#'
#' An updated version of the historical Arbuthnot dataset. Numbers of boys and
#' girls born in the United States between 1940 and 2002.
#'
#'
#' @name present
#' @docType data
#' @format A data frame with 63 observations on the following 3 variables.
#' \describe{
#'   \item{year}{Year.}
#'   \item{boys}{Number of boys born.}
#'   \item{girls}{Number of girls born.}
#'   }
#' @source Mathews, T. J., and Brady E. Hamilton. "Trend analysis of the sex
#' ratio at birth in the United States." National vital statistics reports
#' 53.20 (2005): 1-17.
#' @keywords datasets
#' @examples
#'
#' library(ggplot2)
#'
#' ggplot(present, mapping = aes(x = year, y = boys / girls)) +
#'   geom_line()
"present"