R/HDD_Minneapolis.R

In mosaicCalc: R-Language Based Calculus Operations for Teaching

#' Heating degree days in Minneapolis, Minnesota, USA
#'
#' A "heating degree day" is a measure of weather coldness. It's defined to be the difference
#' between the outdoor ambient temperature and 65 degrees F, but has a value of zero when the ambient 
#' temperature is above 65 degrees. This difference is averaged over time and multiplied by the number 
#' of days in the time period covered. The heating degree day is often used as a measure of the demand for 
#' domestic heating in a locale.
#' 
#' These data report monthly heating degree days. For teaching purposes, the data give an extreme example 
#' of how a relationship (hdd vs year) can be revealed by including a covariate (month). Although interest focusses
#' on the change in temperature over the century the data cover, there is such regular seasonal variation that 
#' no systematic trend over the years is evident unless month is taken into account.
#' 
#' @format A data frame \code{HDD_Minneapolis} with 1412 rows and 4 variables:
#' \itemize{
#' \item year the year
#' \item month the month
#' \item hdd the number of heating degree days for that period.
#' \item loc the location at which the temperature was measured. In the early years, this was downtown Minneapolis.
#' Later, the site was moved to the Minneapolis/Saint-Paul International Airport.
#' }


#'
#' @docType data
#' @name HDD_Minneapolis
#' @usage data(HDD_Minneapolis)
#'
#' @keywords datasets
#'

#' @examples
#' mod_1 <- lm(hdd ~ year, data = HDD_Minneapolis)
#' mod_2 <- lm(hdd ~ year + month, data = HDD_Minneapolis)
"HDD_Minneapolis"