TapeR (version 0.5.3)

E_VOL_AB_HmDm_HT.f: Estimate volume for stem and sections

Description

Estimate volume for a complete stem from bottom to tip or for a section defined by lower and upper diameter or height. Variances for estimated volumes are calculated.

Usage

E_VOL_AB_HmDm_HT.f(
  Hm,
  Dm,
  mHt,
  sHt = 0,
  A = NULL,
  B = NULL,
  iDH = "D",
  par.lme,
  Rfn = list(fn = "sig2"),
  IA = F,
  nGL = 51,
  ...
)

Value

a list holding nine elements:

• E_VOL: Estimated volume (m^3).

• VAR_VOL: Variance of the volume estimate.

• Hm: Height of diameter measurement (m).

• Dm: Diameter measurement (cm).

• Ht: Tree height (m).

• Da: Diameter at lower section threshold (cm).

• Db: Diameter at upper section threshold (cm).

• Ha: Height at lower section threshold (m).

• Hb: Height at upper section threshold (m).

• Rfn: Function applied for estimated or assumed residual variance.

Arguments

Hm

Numeric vector of stem heights (m) along which diameter measurements were taken for calibration. Can be of length 1. Must be of same length as Dm.

Dm

Numeric vector of diameter measurements (cm) taken for calibration. Can be of length 1. Must be of same length as Hm.

mHt

Scalar. Tree height (m).

sHt

Scalar. Standard deviation of stem height. Can be 0 if height was measured without error.

A

Numeric scalar defining the lower threshold of a stem section for volume estimation. Depends on iDH. If iDH = "D", a diameter (cm), if iDH = "H", a height (m). If NULL, section starts at lowest point.

B

Numeric scalar defining the upper threshold of a stem section for volume estimation. Depends on iDH. If iDH = "D", a diameter (cm), if iDH = "H", a height (m). If NULL, section ends at tip.

iDH

Character scalar. Either "D" or "H". Type of threshold for section volume estimation. See A or B.

par.lme

List of taper model parameters obtained by TapeR_FIT_LME.f.

Rfn

list with function name to provide estimated or assumed residual variances for the given measurements, optionally parameters for such functions

IA

Logic scalar. If TRUE, variance calculation of height estimate based on 2-point distribution. If FALSE, variance calculation of height estimate based on Normal approximation.

nGL

Numeric scalar. Number of support points for numerical integration.

...

not currently used

Author

Edgar Kublin

Details

calculates the volume for a complete stem or sections defined by A and B, which might be defined as diameter or height. The parameter Rfn can be used to force the taper curve through the measured points (e.g. by Rfn=list(fn="zero"), cf. resVar).

References

Kublin, E., Breidenbach, J., Kaendler, G. (2013) A flexible stem taper and volume prediction method based on mixed-effects B-spline regression, Eur J For Res, 132:983-997.

See Also

TapeR_FIT_LME.f

Examples

# example data
data(DxHx.df)
# taper curve parameters based on all measured trees
data(SK.par.lme)

#select data of first tree
Idi <- (DxHx.df[,"Id"] == unique(DxHx.df$Id)[1])
(tree1 <- DxHx.df[Idi,])

## Calculate the timber volume for the whole stem
VOL <- E_VOL_AB_HmDm_HT.f(Hm=tree1$Hx[3], 
                          Dm=tree1$Dx[3], 
                          mHt = tree1$Ht[1],
                          sHt = 0, # no height variance assumed
                          par.lme = SK.par.lme)
VOL$E_VOL #' expected value
VOL$VAR_VOL #' corresponding variance
VOL$Rfn

## Calculate the timber volume for the whole stem, using Rfn="zero"
VOL <- E_VOL_AB_HmDm_HT.f(Hm=tree1$Hx[3], 
                          Dm=tree1$Dx[3], 
                          mHt = tree1$Ht[1],
                          sHt = 0, # no height variance assumed
                          par.lme = SK.par.lme,
                          Rfn = list(fn="zero"))
VOL$E_VOL #' expected value
VOL$VAR_VOL #' corresponding variance
VOL$Rfn

## Calculate the timber volume for the whole stem
VOL <- E_VOL_AB_HmDm_HT.f(Hm=tree1$Hx[3], 
                          Dm=tree1$Dx[3], 
                          mHt = tree1$Ht[1],
                          sHt = 1, # no height variance assumed
                          par.lme = SK.par.lme)
VOL$E_VOL #' expected value
VOL$VAR_VOL #' corresponding variance
VOL$Rfn

## Calculate the timber volume for the whole stem, using Rfn="zero"
VOL <- E_VOL_AB_HmDm_HT.f(Hm=tree1$Hx[3], 
                          Dm=tree1$Dx[3], 
                          mHt = tree1$Ht[1],
                          sHt = 1, #  height variance assumed
                          par.lme = SK.par.lme,
                          Rfn = list(fn="zero"))
VOL$E_VOL #' expected value
VOL$VAR_VOL #' corresponding variance
VOL$Rfn

## Calculate the timber volume for a selected section given a height (0.3 - 5 m)
VOL <- E_VOL_AB_HmDm_HT.f(Hm=tree1$Hx[3], 
                          Dm=tree1$Dx[3], 
                          mHt = tree1$Ht[1], 
                          sHt = 1, 
                          par.lme = SK.par.lme, 
                          A=0.3, 
                          B=5, 
                          iDH = "H")
VOL$E_VOL #' expected value
VOL$VAR_VOL #' corresponding variance
VOL$Rfn

## Calculate the timber volume for a selected section given a height (0.3 - 5 m)
VOL <- E_VOL_AB_HmDm_HT.f(Hm=tree1$Hx[3], 
                          Dm=tree1$Dx[3], 
                          mHt = tree1$Ht[1], 
                          sHt = 1, 
                          par.lme = SK.par.lme, 
                          A=0.3, 
                          B=5, 
                          iDH = "H", 
                          Rfn=list(fn="zero"))
VOL$E_VOL #' expected value
VOL$VAR_VOL #' corresponding variance
VOL$Rfn

## Calculate the timber volume for a selected section given a diameter
## threshold (30cm - 15cm) (negative value if A