WWWusage              package:datasets              R Documentation

Internet Usage per Minute

Description:

     A time series of the numbers of users connected to the Internet
     through a server every minute.

Usage:

     WWWusage

Format:

     A time series of length 100.

Source:

     Durbin, J. and Koopman, S. J. (2001) _Time Series Analysis by
     State Space Methods._  Oxford University Press. <URL:
     http://www.ssfpack.com/dkbook/>

References:

     Makridakis, S., Wheelwright, S. C. and Hyndman, R. J. (1998)
     _Forecasting: Methods and Applications._ Wiley.

Examples:

     require(graphics)
     work <- diff(WWWusage)
     par(mfrow = c(2,1)); plot(WWWusage); plot(work)
     ## Not run: 
     require(stats)
     aics <- matrix(, 6, 6, dimnames=list(p=0:5, q=0:5))
     for(q in 1:5) aics[1, 1+q] <- arima(WWWusage, c(0,1,q),
         optim.control = list(maxit = 500))$aic
     for(p in 1:5)
        for(q in 0:5) aics[1+p, 1+q] <- arima(WWWusage, c(p,1,q),
            optim.control = list(maxit = 500))$aic
     round(aics - min(aics, na.rm=TRUE), 2)
     ## End(Not run)

