trtools: Miscellaneous Tools for Teaching Statistics

#' Lifespan of humans and dogs.
#'
#' Hypothetical data of the lifespan of humans and dogs for illustrating accelerated failure time models. The data were constructed so that the lifespan of humans is about seven times that of dogs (i.e., the time to death for dogs is "accelerated" by a factor of about seven relative to humans). 
#'
#' @format A data frame 500 observations and two variables:
#' \describe{
#'    \item{years:}{lifespan in year (i.e., years from birth to death)}
#'    \item{species:}{species (dog or human)}
#' }
#'
#' @note Some of the extreme survival times are obviously not realistic. 
#' 
"lifespan"