| % File src/library/datasets/man/faithful.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2018 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{faithful} |
| \docType{data} |
| \alias{faithful} |
| \encoding{UTF-8} |
| \title{Old Faithful Geyser Data} |
| \description{ |
| Waiting time between eruptions and the duration of the eruption for |
| the Old Faithful geyser in Yellowstone National Park, Wyoming, USA. |
| } |
| \usage{faithful} |
| \format{A data frame with 272 observations on 2 variables. |
| \tabular{rlll}{ |
| [,1] \tab eruptions \tab numeric \tab Eruption time in mins \cr |
| [,2] \tab waiting \tab numeric \tab Waiting time to next |
| eruption (in mins)\cr |
| } |
| } |
| \source{W. Härdle.} |
| \references{ |
| \enc{Härdle}{Haerdle}, 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. |
| \doi{10.2307/2347385}. |
| } |
| \details{ |
| A closer look at \code{faithful$eruptions} reveals that these are |
| heavily rounded times originally in seconds, where multiples of 5 are |
| more frequent than expected under non-human measurement. For a |
| better version of the eruption times, see the example below. |
| |
| There are many versions of this dataset around: Azzalini and Bowman |
| (1990) use a more complete version. |
| } |
| \seealso{ |
| \code{geyser} in package \CRANpkg{MASS} for the Azzalini--Bowman version. |
| } |
| \examples{ |
| require(stats); require(graphics) |
| f.tit <- "faithful data: Eruptions of Old Faithful" |
| |
| ne60 <- round(e60 <- 60 * faithful$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") |
| } |
| \keyword{datasets} |