treevol: Diameter, height and volume for Black Cherry Trees
| treevol | R Documentation |
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.
The records are a slight modification to the original dataframe "trees"
from the datasets R package.
Usage
data(treevol)
Format
A data frame with 31 observations and three variables
- dbh
Diameter at breast height, in cm.
- toth
Total height, in m.
- vtot
Timber volume, in cubic meters.
Source
Ryan TA, Joiner BL, and Ryan BF. 1976. The Minitab Student Handbook. Duxbury Press.
Examples
pairs(treevol, panel = panel.smooth, main = "treevol dataframe")
plot(vtot ~ dbh, data = treevol, log = "xy")
coplot(log(vtot) ~ log(dbh) | toth, data = treevol,
panel = panel.smooth)
summary(m1 <- lm(log(vtot) ~ log(dbh), data = treevol))
summary(m2 <- update(m1, ~ . + log(toth), data = treevol))
anova(m1,m2)
