taper_kozak.94: Kozak (1994) Taper Function.

In sergiocostafh/timbeR: Calculate Wood Volumes from Taper Functions

Kozak (1994) Taper Function.

Description

Kozak (1994) Taper Function.

Usage

taper_kozak.94(dbh, h, hih, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, p)

Arguments

dbh	tree diameter at breast height, in centimeters.
h	total tree height, in meters.
hih	ratio between the height of the section (hi) and the total height (h).
b0, b1, b2, b3, b4, b5, b6, b7, b8, b9	model parameters.
p	numerical value representing the first inflection point calculated in the segmented model of Max and Burkhart (1976).

Value

a numeric value indicating the diameter at the section.

References

Kozak, A. (1994). Development of taper equations by BEC zones and species. Report to the Resources Inventory Branch, B.C. Ministry of Forests. Sept. 1994. Kozak, A. (1997). Effects of multicollinearity and autocorrelation on the variable-exponent taper functions. Canadian Journal of Forest Research, Ottawa, v. 27, n. 5, p. 619-629, 1997.

Examples

library(dplyr)
library(minpack.lm)
library(timbeR)

tree_scaling <- tree_scaling %>%
mutate(did = di/dbh,
       hih = hi/h)

kozak.94 <-  nlsLM(di ~ taper_kozak.94(dbh, h, hih, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, p),
data=tree_scaling,
start=list(b0=1.5,b1=1.5,b2=1,b3=-10,b4=50,b5=-10,b6=34,b7=10,b8=-1,b9=-0.01, p = .1))

sergiocostafh/timbeR documentation built on Feb. 13, 2025, 8:01 p.m.