# Data originally from http://www.amstat.org/publications/jse/v19n1/cafedata.xls
# Modified to work more easily with my students.
#   - Removed all "na" (replaced them with spaces)
#   - Changed all variables names to be more easily read
#
# t: time since cafe opened
# date: Date
# day_code: A code for day (1=Mon)
# day: Day of the week (name)
# sand_sold: Sandwiches sold that day
# sand_waste: Sandwiches wasted that day
# wraps_sold: wraps sold that day
# wraps_waste: wraps wasted that day
# muffins_sold: Muffins sold that day
# muffins_waste: Muffins wasted that day
# cookies_sold: Cookies sold that day
# cookies_waste: Cookies wasted that day
# fruit_sold: Fruit cups sold that day
# fruit_waste: Fruit cups wasted that day
# chips: Bags of chips sold that day
# juices: Juices sold that day
# sodas: Sodas sold that day
# coffees: Coffees sold that day
# soda_and_coffee: Total of sodas and coffees sold that day
# total_sales: Total sales that day
# max_temp: Maximum daily temperature
# total_waste: Total items of waster that day
#
# Suggest factoring the day so that the days are in order
#   this assumes that data are in df
#
# df$day <- factor(df$day,levels=c("Mon","Tue","Wed","Thu","Fri"))