PhenoExtract {phenopix} | R Documentation |
Generic function for the extraction of phenological thresholds
Description
This function extracts phenological thresholds according to different methods. Methods include 'trs', 'derivatives', 'klosterman', 'gu'. See details for the computation of each method.
Usage
PhenoExtract(data, method = "trs", uncert = FALSE,
breaks = 3, envelope = "quantiles",
quantiles = c(0.1, 0.9), plot = TRUE, sf, ...)
Arguments
data |
A list structured as in output from the fitting procedures, such as GuFit, KlostermanFit, ElmoreFit, BeckFit. |
method |
One between 'trs', 'derivatives', 'klosterman', 'gu'. |
uncert |
Should uncertainty on thresholds be computed? It requires that uncertainty be computed in the fitting function. I.e. The function requires the element 'uncertainty' in data beeing non NULL. If is.null(uncertainty) in the data or this item is set to FALSE, uncertainty won't be computed. |
breaks |
Currently unused |
envelope |
One between 'quantiles' and 'min-max'. If 'quantiles', the uncertainty envelope
will be computed as quantiles. Quantiles reported in |
quantiles |
Quantiles to be calculated if envelope='quantiles'. The notation is the same as
to specify quantiles in the |
plot |
Should a diagnostic plot be returned with annotated thresholds? It calls the
function |
sf |
Scaling factors required to normalize the data prior to the fitting. If the function is called by e.g. |
... |
For the plotting function, a number of parameters from generic |
Details
This is a wrapper function that calls PhenoTrs
for method='trs', PhenoDeriv
for method='derivatives', (from package greenbrown
) or PhenoGu
for method='Gu',
and PhenoKl
for method='klosterman' from this package. Please see help of the
single functions for details on the calculation of thresholds.
Value
If uncertainty=FALSE a vector of phenology metrics, otherwise a dataframe.
Author(s)
Gianluca Filippa <gian.filippa@gmail.com>
References
Klosterman ST, Hufkens K, Gray JM, Melaas E, Sonnentag O, Lavine I, Mitchell L, Norman R, Friedl MA, Richardson A D (2014) Evaluating remote sensing of deciduous forest phenology at multiple spatial scales using PhenoCam imagery, Biogeosciences, 11, 4305-4320, doi:10.5194/bg-11-4305-2014.
Gu L, Post WM, Baldocchi D, Black TA, Suyker AE, Verma SB, Vesala T, Wofsy SC. (2009) Characterizing the Seasonal Dynamics of Plant Community Photosynthesis Across a Range of Vegetation Types. In: Phenology of Ecosystem Processes (Ed: Noormets A, Springer New York), pp 35-58.
Zhang X, Friedl MA, Schaaf CB, Strahler AH, Hodges JCF, Gao F, Reed BC, Huete A (2003) Monitoring vegetation phenology using MODIS, Remote Sens. Environ., 84, 471-475.
See Also
PhenoGu
,
PhenoKl
,
PhenoDeriv
,
PhenoTrs
,
PhenoPlot
,
PhenoGu