E_HDx_HmDm_HT.f: Estimate height of given diameter

In TapeR: Flexible Tree Taper Curves Based on Semiparametric Mixed Models

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"),
  ...
)

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

Details

returns the height given a certain diameter.

Value

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

Author(s)

Edgar Kublin

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)

TapeR documentation built on Aug. 16, 2023, 9:07 a.m.