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| Mammals   | R Documentation   |
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Garland(1983) Data on Running Speed of Mammals
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Description
~~~~~~~~~~~

Observations on the maximal running speed of mammal species and their
body mass.

Usage
~~~~~

::

    data(Mammals)

Format
~~~~~~

A data frame with 107 observations on the following 4 variables.

weight
    Body mass in Kg for "typical adult sizes"

speed
    Maximal running speed (fastest sprint velocity on record)

hoppers
    logical variable indicating animals that ambulate by hopping, e.g.
    kangaroos

specials
    logical variable indicating special animals with "lifestyles in
    which speed does not figure as an important factor": Hippopotamus,
    raccoon (Procyon), badger (Meles), coati (Nasua), skunk (Mephitis),
    man (Homo), porcupine (Erithizon), oppossum (didelphis), and sloth
    (Bradypus)

Details
~~~~~~~

Used by Chappell (1989) and Koenker, Ng and Portnoy (1994) to illustrate
the fitting of piecewise linear curves.

Source
~~~~~~

Garland, T. (1983) The relation between maximal running speed and body
mass in terrestrial mammals, *J. Zoology*, 199, 1557-1570.

References
~~~~~~~~~~

Koenker, R., P. Ng and S. Portnoy, (1994) Quantile Smoothing Splines‚Äù
*Biometrika*, 81, 673-680.

Chappell, R. (1989) Fitting Bent Lines to Data, with Applications ot
Allometry, *J. Theo. Biology*, 138, 235-256.

See Also
~~~~~~~~

``rqss``

Examples
~~~~~~~~

::

    data(Mammals)
    attach(Mammals)
    x <- log(weight)
    y <- log(speed)
    plot(x,y, xlab="Weight in log(Kg)", ylab="Speed in log(Km/hour)",type="n")
    points(x[hoppers],y[hoppers],pch = "h", col="red")
    points(x[specials],y[specials],pch = "s", col="blue")
    others <- (!hoppers & !specials)
    points(x[others],y[others], col="black",cex = .75)
    fit <- rqss(y ~ qss(x, lambda = 1),tau = .9)
    plot(fit)

