treestat: Function to compute descriptive statistics at tree-level,...

In biometrics: A Package for Biometrics and Modelling

Function to compute descriptive statistics at tree-level, segregated by a factor (factvar) per sample plot.

Description

Computes several descriptive statistics of variables at the tree-level per sample plot. It can also be be applied to compute them by levels of factor within each available plot.

Usage

treestat(
  data,
  plot.id,
  t = NA,
  y,
  d = NA,
  factvar = NA,
  full = FALSE,
  short.names = TRUE,
  metric = TRUE,
  eng = TRUE,
  want.add.d = FALSE,
  want.add.g = FALSE,
  ...
)

Arguments

data	data frame having the tree list of a sample plot.
plot.id	a string having the plot code-number or unique identificator.
t	(optional) a time variable having the the measurement year (in numeric or character format). The default is NA, in which case the current year is assigned.
y	a string-vector with the name(s) of the random variable(s) to which the descriptive statistics will be computed. By default uses dbh as the name of the variable.
d	(optional) a text with the name of the column of the data having the diameter at breast-heigth. The default is NA. If provided, it is assumed to be in cm. See option metrics to change it to the imperial system.
factvar	a string having de name of the variable used as factor. Each level of the 'factvar' is a category.
full	logical; if TRUE, the output includes some extra descriptive statistics as explained in the datana::descstat() function. The default is FALSE.
short.names	logical; if TRUE, the name of the statistics are short names as explained in the datana::descstat() function. The default is FALSE.
metric	is a logic value, the default is TRUE, thus the diameter d has to be in cm, and the resulting tree-level basal area will be in m^{2}. If metric is FALSE, the diameter d has to be in inches, and the computed tree basal area will be in ft^{2}.
eng	logical; if TRUE (by default), the language of some of the output-column names will be English; if "FALSE" will be Spanish. For instance, the levels of the factor-variable (factvar) is named "level"; otherwise will be "nivel".
want.add.d	logical; if TRUE, the computations will include the diameter at breast-heigth defined in option d, as an extra random variable to be added at the end of the vector y. The default is FALSE.
want.add.g	logical; if TRUE, the computations will include the tree basal area, only possible if option d was defined, as an extra random variable to be added at the end of the vector y. The default is FALSE.
...	aditional options for basic stats functions.

Details

For a given tree list of a sample plot, several descriptive statistics are computed for the selected random variables, by plot and measurement year.

Value

Returns a data frame with the statistics per plot and time for the selected y variables. If factvar is given, the same statistics will be added but segregated by each level (or category) of the factvar.

Author(s)

Christian Salas-Eljatib.

References

• Salas-Eljatib C. 2025. Biometría y Modelación Forestal. Borrador de libro, en revisión. 352 p.

Examples

# Dataframe to be used
df<-biometrics::eucaplot2
#?eucaplot2
head(df)
datana::descstat(df[,c("dap","atot")])
df$parce<-1
## Using the function
treestat(data=df,plot.id="parce",y="atot")
# Now, for two random variables, instead of a single one 
treestat(data=df,plot.id="parce",y=c("dap","atot"))
# If the d is provided, Do you want to add both the diameter
# and the basal area (g), as random variables? 
treestat(data=df,plot.id="parce",y="atot",d="dap",want.add.d=TRUE,want.add.g=TRUE)
## Do the same as before, but adding the computation by a factor

treestat(data=df,plot.id="parce",y="atot",factvar="clase.copa")
df$time<-2025;df$time[1:5]<-2020
df
## Using the function per measurement year
treestat(data=df,plot.id="parce",y="atot",t="time",full=TRUE)
# Do the same as before, but adding the computation by a factor
treestat(data=df,plot.id="parce",y="atot",t="time",
         factvar="clase.copa",full = TRUE)
## same as before, but for two random variables
treestat(data=df,plot.id="parce",y=c("dap","atot"),t="time",
          factvar="clase.copa",full = TRUE)

biometrics documentation built on March 20, 2026, 5:09 p.m.