biometrics (version 1.0.3)

treestat: 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,
  ...
)

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.

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.

Author

Christian Salas-Eljatib.

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.

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)