cuckoos {DAAG}R Documentation

Cuckoo Eggs Data

Description

Length and breadth measurements of 120 eggs lain in the nests of six different species of host bird.

Usage

data(cuckoos)

Format

This data frame contains the following columns:

length
the egg lengths in tenths of millimeters
breadth
the egg breadths in tenths of millimeters
species
a factor with levels
hedge.sparrow, meadow.pipit, pied.wagtail, robin, tree.pipit, wren

Source

Latter, O.H. (1902). The eggs of Cuculus canorus. An Inquiry into the dimensions of the cuckoo's egg and the relation of the variations to the size of the eggs of the foster-parent, with notes on coloration, &c. Biometrika i, 164.

References

Tippett, L.H.C. 1931: "The Methods of Statistics". Williams & Norgate, London.

Examples

 data(cuckoos) 
print("Strip and Boxplots - Example 2.1.2")

attach(cuckoos)
oldpar <- par(las = 2) # labels at right angle to axis.
stripchart(length ~ species) 
boxplot(split(cuckoos$length, cuckoos$species),
         xlab="Length of egg", horizontal=TRUE)
detach(cuckoos)
par(oldpar)
pause()

print("Summaries - Example 2.2.2")
sapply(split(cuckoos$length, cuckoos$species), sd)
pause()

print("Example 4.1.4")
wren <- split(cuckoos$length, cuckoos$species)$wren
median(wren)
n <- length(wren)
sqrt(pi/2)*sd(wren)/sqrt(n)  # this s.e. computation assumes normality

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