glsControl {nlme}

Control Values for gls 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 gls function.

Usage

glsControl(maxIter, msMaxIter, tolerance, msTol, msVerbose,
           singular.ok, returnObject = FALSE, apVar, .relStep,
           opt = c("nlminb", "optim"), optimMethod,
           minAbsParApVar, natural, sigma = NULL)

Arguments

maxIter

maximum number of iterations for the gls optimization algorithm. Default is 50.

msMaxIter

maximum number of iterations for the optimization step inside the gls optimization. Default is 50.

tolerance

tolerance for the convergence criterion in the gls algorithm. Default is 1e-6.

msTol

tolerance for the convergence criterion of the first outer iteration when optim is used. Default is 1e-7.

msVerbose

a logical value passed as the trace control value to the chosen optimizer (see documentation on that function). Default is FALSE.

singular.ok

a logical value indicating whether non-estimable coefficients (resulting from linear dependencies among the columns of the regression matrix) should be allowed. Default is FALSE.

returnObject

a logical value indicating whether the fitted object should be returned when the maximum number of iterations is reached without convergence of the algorithm. 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).

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.

natural

logical. Should the natural parameterization be used for the approximate variance calculations? Default is TRUE.

sigma

optionally a positive number to fix the residual error at. If NULL, as by default, or 0, sigma is estimated.

Value

a list with components for each of the possible arguments.

Author(s)

José Pinheiro and Douglas Bates [e-mail]; the sigma option: Siem Heisterkamp and Bert van Willigen.

See Also

gls

Examples

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