rBDAT (version 1.0.0)

getForm: Get estimated mean of form factor q03

Description

this function returns for a given dbh-height-class and species the estimated mean of the q03-distribution, which can be considered as a form factor for different inventories (i.e. NFI 1, NSoG, IS08, NFI3).

Usage

getForm(tree, ...)
# S3 method for data.frame
getForm(tree, inv = NULL, mapping = NULL, ...)
# S3 method for list
getForm(tree, inv = NULL, mapping = NULL, ...)
# S3 method for datBDAT
getForm(tree, inv = NULL, mapping = NULL, ...)

Value

vector of form factor q03.

Arguments

tree

either a data.frame or a list containing the variables needed to decribe a tree, i.e. spp, D1, H, and optionally H1, D2, H2. See buildTree for details and parameter mapping for mapping of variable names

...

passing arguments to methods.

inv

integer, indicator for which inventory the form factor should be returned; defaults to 1 (0=volume tables of Grundner-Schwappach 1921, 1=NFI1, 2=NSoG, 3=IS08, 4=NFI3). Any other value is silently set back to inv=1.

mapping

mapping of variable names in case a data.frame is given into parameter tree between colnames(tree) and required parameter names.

Methods (by class)

• getForm(data.frame): transforming data.frame before calling getForm using buildTree

• getForm(list): transforming list before calling getForm using buildTree

• getForm(datBDAT): class method for class datBDAT

Details

This function returns the estimated mean of the q03-distribution for a given dbh-height-class and species. The q03-distribution is the ratio between the diameter in 30% of tree height and 5% of tree height and describes the form of the taper curve. This value can be returned for different inventories, during which upper stem diameters have been sampled.

Only spp, D1 and H are used to estimate mean q03, if provided and H1 equals 1.3m, otherwise dbh is estimated using BDAT functions (i.e. getDiameter(tree, Hx=1.3)).

Examples

tree <- data.frame(spp = c(1, 1), D1 = c(30, 25), H = c(25, 25))
tree <- buildTree(tree, check = "form", vars = list(inv = 1))
str(tree)
getForm(tree) # default is 'inv=1'
getForm(tree, inv = 0) # taper form of BDAT from model fit
getForm(tree, inv = 1) # NFI 1 (without NSoG)
getForm(tree, inv = 2) # NSoG = New States of Germany
getForm(tree, inv = 3) # carbon inventory 2008
getForm(tree, inv = 4) # NFI 3 (reunificated Germany)