Stats 4540/6571
         Some Splus Commands for Creating, Plotting Time Series


 NOTE: If you want some information on working in Splus, you can check
the following website

     www.math.mun.ca/~sneddon/st4590

 In particular, you can look at the links on "Splus help" and the 
"lab sessions".

 The following Splus commands were used to generate the attached plots.
 Key commands: cts (calendar time series)
               rts (regularly spaced time series)
	       tsplot (plot a time series)

#######################

par(mfrow=c(3,1))

plot(fruitimp.vec, type = 'l', xlab = "Time", ylab = "Million $")
 mtext("Canadian Monthly Fruit Imports, 1980-2001")

fruitimp.ts <- cts(fruitimp.vec, start = dates("01/01/1980"),
units = "months")

# Another way to create the time series, using rts
# fruitimp.ts <- rts(fruitimp.vec, start = c(1980, 1),  frequency = 12)

tsplot(fruitimp.ts)
mtext("Canadian Monthly Fruit Imports, using cts and tsplot")

fruitimp.ts.small <- cts(fruitimp.vec[1:48], start = dates("01/01/1980"),
                        units = "months")
tsplot(fruitimp.ts.small)
mtext("Canadian Monthly Fruit Imports, 1980-1984")

###########################################################

par(mfrow =c (2,1)) 

 # Time series of the Southern Oscillation Index (SOI). This is the
 # indicator of the atmospheric phenomenon El Nino. It is the pressure
 # difference between Darwin, Australia and Tahiti.

 soi.vec.ts <- cts(soi.vec,start=("01/01/1882"), units = "months")
 mtext("Southern Oscillation Index (El Nino)") 

 tsplot(soi.vec.ts)

 Nice plot??

 # Let's look at last 22 months of data:

 tsplot(soi.vec.ts[1200:1464]) 
 mtext("Southern Oscillation Index (El Nino)")