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.

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)