TapeR (version 0.5.3)

E_HDx_HmDm_HT.f: Estimate height of given diameter

Description

Calibrates a taper curve based on at least one diameter measurement and returns the height of a given diameter

Usage

E_HDx_HmDm_HT.f(
  Dx,
  Hm,
  Dm,
  mHt,
  sHt = 0,
  par.lme,
  Rfn = list(fn = "sig2"),
  ...
)

Value

A scalar. Estimated height (m) given a diameter.

Arguments

Dx

Scalar. Diameter for which to return height.

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.

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

...

not currently used

Author

Edgar Kublin

Details

returns the height given a certain diameter.

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,])

## Predict the taper curve based on the diameter measurement in 2 m
## height and known height 
tc.tree1 <- E_DHx_HmDm_HT.f(Hx=1:tree1$Ht[1], 
                            Hm=tree1$Hx[3],
                            Dm=tree1$Dx[3], 
                            mHt = tree1$Ht[1], 
                            sHt = 0, 
                            par.lme = SK.par.lme)
#plot the predicted taper curve
plot(tc.tree1$Hx, tc.tree1$DHx, type="l", las=1)

## Calculate the height given a certain diameter threshold, say 8.5 cm
ht.tree1.d8.5 <- E_HDx_HmDm_HT.f (Dx=8.5, 
                                  Hm=tree1$Hx[3],
                                  Dm=tree1$Dx[3], 
                                  mHt = tree1$Ht[1], 
                                  sHt = 1, 
                                  par.lme = SK.par.lme,
                                  Rfn=list(fn="sig2")) 
# add to plot
points(x=ht.tree1.d8.5, y=8.5, pch=8, col=2, cex=2)