janka {SemiPar}

Janka hardness data

Description

The janka data frame has 36 observations on Australian timber samples.

Usage

data(janka)

Format

This data frame contains the following columns:

dens

a measure of density of the timber.

hardness

the Janka hardness (structural property) of the timber.

Source

Williams, E.J. (1959) Regression Analysis, New York: John Wiley & Sons.

References

Ruppert, D., Wand, M.P. and Carroll, R.J. (2003)
Semiparametric Regression Cambridge University Press.
http://stat.tamu.edu/~carroll/semiregbook/

Examples

library(SemiPar)
data(janka)
attach(janka)
plot(dens,hardness)