getVolume: Get segment volume for one or many trees

In rBDAT: Implementation of BDAT Tree Taper Fortran Functions

Get segment volume for one or many trees

Description

Function to get segment volume over or under bark for a tree of dimension D1, possible D2, and H. Volume is calculated for a given segment defined by A and B, which might be specified as heights or diameters.

Usage

getVolume(tree, ...)

## S3 method for class 'data.frame'
getVolume(tree, AB = NULL, iAB = "H", bark = TRUE, mapping = NULL, ...)

## S3 method for class 'list'
getVolume(tree, AB = NULL, iAB = "H", bark = TRUE, mapping = NULL, ...)

## S3 method for class 'datBDAT'
getVolume(tree, AB = NULL, iAB = "H", bark = TRUE, mapping = NULL, ...)

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.
AB	list with heights or diameters A and B of section for which volume over or under bark should be calculated. Additionally, add in sl for the segment length over which the integral should be calculated. See details.
iAB	character indicating how to interpret given A and B values. Either "H" (the default), "Dob" (diameter over bark) or "Dub" (diameter under bark). Could be of length one or two, depending on whether A and B are both height or diameter variables or not. See examples.
bark	boolean of length one indicator for whether required volume should include bark volume or not. Defaults to TRUE. Coerced to logical by as.logical(bark[1]).
mapping	mapping of variable names in case a data.frame is given into parameter tree between colnames(tree) and required parameter names. See details.

Details

iAB can be a vector of length two, indicating how to interpret A and B. Hence, one can calculate volume between a given height and a given diameter, either over or under bark. If of length one, it is assumed the indicator applies to both A and B.

Internally, provided diameters in A or B are tranformed to heights by BDATHXDX if iAB="dob" or by BDATHXDXOR if iAB="dub".

Value

vector of same length as tree, returning the required volume in cubic meter.

Methods (by class)

• data.frame: transforming data.frame before calling getVolume using buildTree

• list: transforming data.frame before calling getVolume using buildTree

• datBDAT: class method for class datBDAT

See Also

BDATVOLABMR and BDATVOLABOR for a BDAT-type wrapper and function to keep back-compatability. To get total coarse wood volume (>=7m diameter over bark) BDAT-type functions are BDATVOLDHMR and BDATVOLDHOR.

Examples

## default return with just one or several trees given is total coarse wood
## volume over bark, i.e. stock volume (in german: Vfm m.R.)
getVolume(list(spp = 1, D1 = 30, H = 25))

## first using a data.frame and height information
tree <- data.frame(spp = 1, D1 = 30, H = 25, A = 0.1, B = 10)
getVolume(tree) # iAB = "H", bark = TRUE, mapping = NULL as default values
getVolume(tree, iAB = "H", bark = FALSE, mapping = NULL)

## now, use diameter information
tree <- data.frame(spp = 1, D1 = 30, H = 25, A = 30, B = 7)
getVolume(tree, iAB = "Dob", bark = TRUE, mapping = NULL)

## now use both diameter and height information
tree <- data.frame(spp = 1, D1 = 30, H = 25, A = 0, B = 7)
getVolume(tree, iAB = c("H", "Dob"), bark = TRUE, mapping = NULL)
## is equivalent to the original BDAT-function:
BDATVOLDHMR(1, 30, 0, 0, 0, H = 25)
## and
getVolume(tree, iAB = c("H", "Dob"), bark = FALSE, mapping = NULL)
## is equivalent to:
BDATVOLDHOR(1, 30, 0, 0, 0, H = 25)

## use a misnamed data.frame and mapping argument
tree <- data.frame(BDATCode = 1, dbh = 30, h = 25, l = 30, u = 7)
getVolume(tree,
  iAB = "Dob", bark = TRUE,
  mapping = c("BDATCode" = "spp", "dbh" = "D1", "h" = "H", "l" = "A", "u" = "B")
)

## using a list to provide the data
tree <- list(
  spp = c(1, 1), D1 = c(30, 25), H = c(25, 30), A = c(30, 25),
  B = c(7, 7)
)
getVolume(tree, iAB = "Dob") #' defaults: bark = TRUE, mapping = NULL
getVolume(tree, iAB = "Dob", bark = FALSE) #' defaults: mapping = NULL

## using a misnamed list and mapping argument
tree <- list(
  BDATCode = c(1, 1), dbh = c(30, 25), H = c(25, 30),
  A = c(0.1, 0.1), B = c(1, 1)
)
getVolume(tree, mapping = c("BDATCode" = "spp", "dbh" = "D1"))

## using parameter AB to provide the segment data
## in this case a cross join between tree and AB is produced and evaluated
tree <- list(BDATCode = c(1, 1), dbh = c(30, 25), H = c(25, 30))
AB <- list(A = c(0.1, 1), B = c(1, 2))
getVolume(tree, AB, iAB = "H", bark = TRUE, mapping = c("BDATCode" = "spp", "dbh" = "D1"))

## effect of adjusting 'sl'
tree <- list(spp = 1, D1 = 30, H = 25)
getVolume(tree = tree, AB = list(A = 0.1, B = 5.1, sl = 2)) # default
getVolume(tree = tree, AB = list(A = 0.1, B = 5.1, sl = 1))
getVolume(tree = tree, AB = list(A = 0.1, B = 5.1, sl = 0.1))
getVolume(tree = tree, AB = list(A = 0.1, B = 5.1, sl = 0.01))

## compare Smalian formula to mid-diameter volume for sl=5
R1 <- getDiameter(tree, Hx = 1.3) / 100 / 2 # radius in m
R2 <- getDiameter(tree, Hx = 6.3) / 100 / 2 # radius in m
h <- 5
pi * ((R1 + R2) / 2)^2 * h # average of bottom and top diameter
(h * pi) / 3 * (R1^2 + R1 * R2 + R2^2) # truncated-cone volume
getVolume(tree, AB = list(A = 1.3, B = 6.3, sl = 5)) # mid-diameter volume
getVolume(tree, AB = list(A = 1.3, B = 6.3, sl = 0.01)) # physical volume

rBDAT documentation built on Oct. 14, 2022, 5:07 p.m.