setTapeSoptions {TapeS} | R Documentation |
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)
Arguments
Rfn |
setting for residuals error matrix, defaults to |
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.
Value
by defaults, sets options()$TapeS_Rfn
to "sig2"
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()