pub fn loblolly() -> Result<DataFrame, PolarsError>Expand description
§Growth of Loblolly pine trees
§Description:
The ‘Loblolly’ data frame has 84 rows and 3 columns of records of the growth of Loblolly pine trees.
§Usage:
Loblolly
§Format:
An object of class ‘c(“nfnGroupedData”, “nfGroupedData”, “groupedData”, “data.frame”)’ containing the following columns:
- height a numeric vector of tree heights (ft).
- age a numeric vector of tree ages (yr).
- Seed an ordered factor indicating the seed source for the tree. The ordering is according to increasing maximum height.
§Details:
This dataset was originally part of package ‘nlme’, and that has methods (including for ‘[’, ‘as.data.frame’, ‘plot’ and ‘print’) for its grouped-data classes.
§Source:
Kung, F. H. (1986), Fitting logistic growth curve with predetermined carrying capacity, in Proceedings of the Statistical Computing Section, American Statistical Association, 340-343.
Pinheiro, J. C. and Bates, D. M. (2000) Mixed-effects Models in S and S-PLUS, Springer.
§Examples:
require(stats); require(graphics)
plot(height ~ age, data = Loblolly, subset = Seed == 329,
xlab = "Tree age (yr)", las = 1,
ylab = "Tree height (ft)",
main = "Loblolly data and fitted curve (Seed 329 only)")
fm1 <- nls(height ~ SSasymp(age, Asym, R0, lrc),
data = Loblolly, subset = Seed == 329)
age <- seq(0, 30, length.out = 101)
lines(age, predict(fm1, list(age = age)))