TapeS (version 0.13.2)

setTapeSoptions: Set and get options for the TapeS-package

Description

Function to set and get options on how the TapeS-package works.

Usage

setTapeSoptions(Rfn = list(fn = "sig2"), mono = TRUE)
getTapeSoptions(name = NULL)

Value

by defaults, sets options()$TapeS_Rfn to "sig2"

Arguments

Rfn

setting for residuals error matrix, defaults to "sig2", see details.

mono

logical, defaults to true. If calibrated taper curve is non-monotonic at stem base, an support diameter is added.

name

name of options to be returned

Details

So far, only two options are implemented: TapeS_Rfn and TapeS_mono. Teh first defaults to "sig2" (i.e. 'sigma squared') and the second to "TRUE".

The TapeR-taper curves can be evaluated in basically two ways: (i) either as defined in the TapeR-package, i.e. the diameters and volumes are estimated using the estimated error structure and find an optimal taper curve given the measured diameters or (ii) by interpolating the measured diameters, i.e. forcing the estimated taper curve through those measurements by setting the residual error structure to zero. See Kublin et al. (2013), p.987 bottom left. Technically, forcing the taper curve through the measurements is achieved by setting the residual error matrix R to zero, that is Rfn = list(fn="zero"). Defaults to Rfn = list(fn="sig2"). Besides, one can defined other functions about assumptions about the errors at the measurement positions, see resVar for options.

NB: Caution is required in applying Rfn=list(fn="zero"), since forcing the taper curve through too many points might lead to singularities or implausible results!

The option 'mono=TRUE' assures that no taper curve is generated which shows lower diameter in lower heights, possibly adding a support diameter at 1% of tree height.

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.

Examples

## reset option TapeS_Rfn to "sig2", i.e. model based errors by
setTapeSoptions(Rfn = list(fn="sig2"))
## or to force the taper curve through the  measurements, set
options("TapeS_Rfn" = list(fn="zero"))
## see the actual state of options by
options()[grep("^TapeS_", names(options()))]
## or easier
getTapeSoptions()