Diameter, Height and Volume for Black Cherry Trees

Description

This data set provides measurements of the diameter, height and volume of timber in 31 felled black cherry trees. Note that the diameter (in inches) is erroneously labelled Girth in the data. It is measured at 4 ft 6 in above the ground.

Usage

trees

Format

A data frame with 31 observations on 3 variables.

Source

⁠Meyer H. A. (1953). Forest Mensuration. Penns Valley Publishers.

⁠Ryan T. A., Joiner B. L., Ryan B. F. (1976). The Minitab Student Handbook. Duxbury Press, North Scituate, MA. ISBN 087150359X.

References

⁠Atkinson A. C. (1986). Plots, Transformations and Regression. Oxford University Press. ISBN 978-0198533597.

Examples

require(stats); require(graphics)
pairs(trees, panel = panel.smooth, main = "trees data")
plot(Volume ~ Girth, data = trees, log = "xy")
coplot(log(Volume) ~ log(Girth) | Height, data = trees,
       panel = panel.smooth)
summary(fm1 <- lm(log(Volume) ~ log(Girth), data = trees))
summary(fm2 <- update(fm1, ~ . + log(Height), data = trees))
step(fm2)
## i.e., Volume ~= c * Height * Girth^2  seems reasonable