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, Koopman SJ (2001). Time Series Analysis by State Space Methods. Oxford University Press. ISBN 0198523548.
Data was available from the book website, now archived at https://web.archive.org/web/20020304222057/http://www.ssfpack.com/dkbook/.

References

Makridakis SG, Wheelwright SC, Hyndman RJ (1997). Forecasting: Methods and Applications. John Wiley & Sons. ISBN 978-0471532330.

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)