partGLFitLRC: partGLFitLRC

In REddyProc: Data processing and plotting utilities of (half-)hourly eddy-covariance measurements

Description

Optimize rectangular hyperbolic light response curve against data in one window and estimate uncertainty

Usage

partGLFitLRC(dsDay, E0, sdE0, RRefNight, controlGLPart = partGLControl(), 
    lastGoodParameters)

Arguments

dsDay	data.frame with columns NEE, Rg, Temp_C, VPD, and no NAs in NEE
E0	temperature sensitivity of respiration
sdE0	standard deviation of E_0.n
RRefNight	basal respiration estimated from night time data, used as starring value and prior estimate
controlGLPart	further default parameters (see partGLControl)
lastGoodParameters	numeric vector of last good theta

Details

Optimization is performed for three initial parameter sets that differ by beta0 (*1.3, *0.8). From those three, the optimization result is selected that yielded the lowest misfit. Starting values are: k=0, beta=interpercentileRange(0.03,0.97) of respiration, alpha=0.1, R_ref from nightTime estimate. E0 is fixed to the night-time estimate, but varied for estimating parameter uncertainty.

If controlGLPart.l$nBootUncertainty == 0L then the covariance matrix of the parameters is estimated by the Hessian of the LRC curve at optimum. Then, the additional uncertainty and covariance with uncertaint E0 is neglected.

If controlGLPart.l$nBootUncertainty > 0L then the covariance matrix of the parameters is estimated by a bootstrap of the data. In each draw, E0 is drawn from N ~ (E_0, sdE_0).

Value

a list, If none of the optimizations from different starting conditions converged, the parameters are NA

opt.parms.V	numeric vector of optimized parameters including the fixed ones and including E0
iOpt	index of parameters that have been optimized , here including E0, which has been optimized prior to this function.
initialGuess.parms.V.n	the initial guess from data
covParms	numeric matrix of the covariance matrix of parameters, including E0

Author(s)

TW, MM (Department for Biogeochemical Integration at MPI-BGC, Jena, Germany)

See Also

partGLFitLRCWindows

parmGLOptimLRCBounds

REddyProc documentation built on May 2, 2019, 5:19 p.m.