gnlsControl: Control Values for gnls Fit

Description

The values supplied in the function call replace the defaults and a list with all possible arguments is returned. The returned list is used as the control argument to the gnls function.

Usage

gnlsControl(maxIter = 50, nlsMaxIter = 7, msMaxIter = 50, minScale = 0.001,
            tolerance = 1e-6, nlsTol = 0.001, msTol = 1e-7,
            returnObject = FALSE, msVerbose = FALSE,
            apVar = TRUE, .relStep =,
            opt = c("nlminb", "optim"), optimMethod = "BFGS",
            minAbsParApVar = 0.05, sigma = NULL)

Value

a list with components for each of the possible arguments.

Arguments

maxIter: maximum number of iterations for the gnls optimization algorithm. Default is 50.
nlsMaxIter: maximum number of iterations for the nls optimization step inside the gnls optimization. Default is 7.
msMaxIter: maximum number of iterations for the optimization step inside the gnls optimization. Default is 50.
minScale: minimum factor by which to shrink the default step size in an attempt to decrease the sum of squares in the nls step. Default 0.001.
tolerance: tolerance for the convergence criterion in the gnls algorithm. Default is 1e-6.
nlsTol: tolerance for the convergence criterion in nls step. Default is 1e-3.
msTol: tolerance for the convergence criterion of the first outer iteration when optim is used. Default is 1e-7.
returnObject: a logical value indicating whether the fitted object should be returned with a warning (instead of an error via stop()) when the maximum number of iterations is reached without convergence of the algorithm.
msVerbose: a logical value passed as the trace argument to the optimizer chosen by opt; see documentation on that. Default is FALSE.
apVar: a logical value indicating whether the approximate covariance matrix of the variance-covariance parameters should be calculated. Default is TRUE.
.relStep: relative step for numerical derivatives calculations. Default is .Machine$double.eps^(1/3) (about 6e-6).
opt: the optimizer to be used, either "nlminb" (the current default) or "optim" (the previous default).
optimMethod: character - the optimization method to be used with the optim optimizer. The default is "BFGS". An alternative is "L-BFGS-B".
minAbsParApVar: numeric value - minimum absolute parameter value in the approximate variance calculation. The default is 0.05.
sigma: optionally a positive number to fix the residual error at. If NULL, as by default, or 0, sigma is estimated.

Author

José Pinheiro and Douglas Bates bates@stat.wisc.edu; the sigma option: Siem Heisterkamp and Bert van Willigen.

Examples

Run this code

# decrease the maximum number of iterations and request tracing
gnlsControl(msMaxIter = 20, msVerbose = TRUE)