Average monthly milk production per cow over 14 years (January 1962 - December 1975).
Source
Makridakis, Wheelwright and Hyndman (1998) Forecasting:
methods and applications, John Wiley & Sons: New York. Chapter 2.
References
Cryer (1986) Time series analysis, Duxbury Press:
Belmont.
Examples
par(mfrow=c(2,1))
plot(milk,xlab="Year",ylab="pounds",
main="Monthly milk production per cow")
milk.adj <- milk/monthdays(milk)*365.25/12
plot(milk.adj,xlab="Year",ylab="pounds",
main="Adjusted monthly milk production per cow")