\inputencoding{latin1}
\HeaderA{faithful}{Old Faithful Geyser Data}{faithful}
\keyword{datasets}{faithful}
\begin{Description}\relax
Waiting time between eruptions and the duration of the eruption for
the Old Faithful geyser in Yellowstone National Park, Wyoming, USA.
\end{Description}
\begin{Usage}
\begin{verbatim}faithful\end{verbatim}
\end{Usage}
\begin{Format}\relax
A data frame with 272 observations on 2 variables.
\Tabular{rlll}{
[,1]  & eruptions  & numeric  & Eruption time in mins \\{}
[,2]  & waiting    & numeric  & Waiting time to next
eruption (in mins)\\
}
\end{Format}
\begin{Details}\relax
A closer look at \code{faithful\$eruptions} reveals that these are
heavily rounded times originally in seconds, where multiples of 5 are
more frequent than expected under non-human measurement.  For a
better version of the eruption times, see the example below.

There are many versions of this dataset around: Azzalini and Bowman
(1990) use a more complete version.
\end{Details}
\begin{Source}\relax
W. Härdle.
\end{Source}
\begin{References}\relax
Härdle, W. (1991)
\emph{Smoothing Techniques with Implementation in S}.
New York: Springer.

Azzalini, A. and Bowman, A. W. (1990).
A look at some data on the Old Faithful geyser.
\emph{Applied Statistics} \bold{39}, 357--365.
\end{References}
\begin{SeeAlso}\relax
\code{geyser} in package \pkg{MASS} for the Azzalini--Bowman version.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
require(stats); require(graphics)
f.tit <-  "faithful data: Eruptions of Old Faithful"

ne60 <- round(e60 <- 60 * faithful$eruptions)
all.equal(e60, ne60)             # relative diff. ~ 1/10000
table(zapsmall(abs(e60 - ne60))) # 0, 0.02 or 0.04
faithful$better.eruptions <- ne60 / 60
te <- table(ne60)
te[te >= 4]                      # (too) many multiples of 5 !
plot(names(te), te, type="h", main = f.tit, xlab = "Eruption time (sec)")

plot(faithful[, -3], main = f.tit,
     xlab = "Eruption time (min)",
     ylab = "Waiting time to next eruption (min)")
lines(lowess(faithful$eruptions, faithful$waiting, f = 2/3, iter = 3),
      col = "red")
\end{ExampleCode}
\end{Examples}

