avg_tree_curve: Generate the curve of a forest's average tree using the Kozak...

In forestmangr: Forest Mensuration and Management

Generate the curve of a forest's average tree using the Kozak taper model

Description

Generate a ggplot curve of a forest's average tree using the Kozak taper model (Kozak, Munro and Smith, 1969).

Usage

avg_tree_curve(
  df,
  d,
  dbh,
  h,
  th,
  facet = NA,
  color = NA,
  eq = TRUE,
  mirror = TRUE
)

Arguments

df	A data frame.
d	Quoted name of the section diameter variable, in cm.
dbh	Quoted name of the diameter at breast height variable, in cm.
h	Quoted name of the section height variable, in meters.
th	Quoted name of the total height variable, in meters.
facet	Optional argument. If supplied with the Quoted name of a factor variable(s), this variable is used to divide the plot into facets. Default: NA.
color	Quoted name of a variable. If supplied, this variable will be used to classify the data by color. Default: NA.
eq	if TRUE, Kozak's taper model is adjusted and the equation is shown on the plot. Default TRUE
mirror	if TRUE, the plot will be mirrored, to resemble the shape of a tree. Default: TRUE

Value

A ggplot object.

Author(s)

Sollano Rabelo Braga [e-mail]

References

Kozak, A., Munro, D. D. and Smith, J. H. G. (1969) Taper Functions and their Application in Forest Inventory, The Forestry Chronicle, 45, pp. 278–283.

Examples

library(forestmangr)
data("exfm7")
head(exfm7)

# Get the data's average tree curve inserting the section diameter and height,
# total height and dbh variables: 
avg_tree_curve(df=exfm7,d="di_wb",dbh="DBH",h="hi",th="TH",eq=FALSE)

# It's possible to get the average tree curve of each strata with the facet arg.,
# and divide the data by color with the color argument:
avg_tree_curve(exfm7,"di_wb","DBH","hi","TH","STRATA","GENCODE",FALSE)

forestmangr documentation built on Sept. 15, 2024, 1:06 a.m.