faithful {datasets} R Documentation

## 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.
 [,1] eruptions numeric Eruption time in mins [,2] waiting numeric Waiting time to next eruption (in mins)

### Details

A closer look at `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 eruptions times, see the example below.

There are many versions of this dataset around: Azzalini and Bowman (1990) use a more complete version.

W. Härdle.

### References

Härdle, W. (1991) 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. Applied Statistics 39, 357–365.

`geyser` in package MASS for the Azzalini–Bowman version.

### Examples

```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")
```

[Package datasets version 2.5.0 Index]